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The OPCW Douma Leaks Part 2: We Need To Talk About Henderson

January 17, 2020

By Bellingcat Investigation Team

Executive Summary

  1. Henderson was an employee of the OPCW, but the organisation clearly did not consider him to be part of the FFM.
  2. Henderson delivered his report outside of protocol with less than a day before the final FFM report was published.
  3. Three independent engineering studies commissioned by the FFM contradict Henderson’s findings.
  4. Henderson’s report is fundamentally flawed by the assumption that these cylinders could not have fallen from an altitude of less than 500 meters.
  5. The methodology that Henderson employed for this report was not adequate for this task.

In our first article in this series, we examined the claims of “Alex” and the documents released by WikiLeaks. In this article, we will look at a report by a self-described “engineering sub-team” of the Organisation for the Prohibition of Chemical Weapons (OPCW), headed by Ian Henderson. 

Henderson’s report examines the impact of what appear to be two chlorine cylinders associated with a chemical attack in Douma on April 7, 2018.  One of these cylinders was found on a balcony at Location 2 and one in a bedroom at Location 4. Henderson’s report concluded that it is more likely the cylinders were manually placed than dropped from altitude. Although Henderson’s report claims to have used the same data as the Fact Finding Mission (FFM) of the OPCW, it must be emphasised that three independent engineering studies commissioned by the FFM contradict Henderson’s findings

Henderson’s report was first leaked on May 13, 2019, however, the Russian Federation appears to have had access to it well before this date. On April 26, 2019, the permanent representative of the Russian Federation to the OPCW sent a critique of the final FFM report to the OPCW, sections of which were remarkably similar to Henderson’s report. The Director-General of the OPCW said that he learned this report may have been leaked as early as March 2019. 

Taking a closer look at Henderson’s report helps to explain why it is not consistent with the FFM’s conclusions. It is evident that Henderson’s methodology was fundamentally flawed, and that a major assumption was made about the altitude from which these cylinders could have fallen. There also appear to be several errors or inaccuracies in other aspects of the report.

As with Part 1 of this series, we have included a list of the documents leaked by WikiLeaks in an attempt to make the timeline of this event more transparent.

  1. Alex’s initial email of complaint
  2. PPB email chain
  3. First draft report
  4. Second draft report
  5. Interim OPCW report
  6. Information security reminder
  7. Toxicology minutes
  8. Emails regarding toxicology minutes
  9. Email chain regarding Henderson’s report
  10. Henderson’s engineering report
  11. Final report
  12. Henderson’s memo
  13. Alex’s second email of complaint email

Who Is Henderson?

Ian Henderson does indeed seem to have been a real employee of the OPCW, and the leaked documents do indicate that he deployed to Douma in support of the FFM. A memo sent by Henderson, dated March 14, 2019, appears to be an email from Henderson and describes his work. He stated he had visited the scene in Douma, and afterward spent five weeks in charge of the OPCW control post inside Syria. 

On return from Douma, Henderson claims to have been assigned the task of “analysis and assessment of the ballistics of the two cylinders”. After this point, Henderson claims to have been “excluded from the work”, presumably by the FFM team, but that he chose to continue working on his engineering report.

Extract from Henderson’s memo from 14th March 2019, claiming to have been excluded by the FFM “core team”.

However, in an earlier email chain regarding Henderson’s report, dated from February 26, 2019, Henderson only mentions that he was “tasked to contribute to the review of ‘location and munition’”. He also explicitly states that he has been excluded from the work because he is not a member of what he refers to as the “‘core team’”.

Extract from Henderson’s email dated 26th Feb 2019, from an email chain regarding Henderson’s report.

In this earlier email from February, Henderson does not appear to mention being explicitly tasked to create this report. Without further information it is impossible to identify who told Henderson to do exactly what task, or why. However, he does claim to have received some form of authorisation from the Director of Inspectorate (DoI) in order to gain access to engineering computational tools to continue his work. 

As such, it seems Henderson did have approval to do this work at some level of the OPCW. Without a detailed knowledge of the inner structure of the OPCW, it is not possible to assess whether this authority was sufficient for the work he was undertaking. As we will see, it seems at least one senior member of the OPCW was shocked when they found out Henderson had created this report.

Henderson’s Status As A Member Of The FFM

The main reason why Henderson may have been “excluded from the work” of the FFM is that the OPCW did not regard him as being part of the FFM team itself, and because the FFM is regarded as a highly confidential mission. Although he deployed in support of the FFM in Douma and was clearly involved in gathering evidence, this does not appear to qualify him as actually being a part of the FFM in the eyes of the OPCW. 

The OPCW has previously denied Henderson was in the FFM, explaining that he “was tasked with temporarily assisting the FFM with information collection at some sites in Douma”. WikiLeaks also leaked an internal email from the Sebastien Braha, Chief of Cabinet of the Director General of the OPCW, questioning why Henderson had carried out this work “outside FFM authority… by someone who was not part of the FFM?”. This email was clearly never intended to be public, and Braha had no reason to obscure Henderson’s role.

Extract from email dated 28 Feb 2019, from an email chain regarding Henderson’s report. 

Despite Henderson’s distinction between the “FFM team members” and the “core team” and Alex’s complaints, it is clear that as an institution, the OPCW only regarded what Henderson describes as the “core team” as being the FFM. This did not include Henderson. 

When Did Henderson Submit This Work?

Henderson claims to have first attempted to submit his document “starting from 15 February 2019”, however, at the time of writing the earliest evidence we have of Henderson attempting to deliver his report appears to have been on February 27, 2019, two days before the final report was due to be published. The person he is emailing, Boban Cekovic, appears to have received contradictory information about how this report should be handled and offers to check. 

Emails between Cekovic and Henderson, from an email chain regarding Henderson’s report. 

(The pdF of the emails above, which were leaked by WikiLeaks, also, rather bizarrely, contain an email from a completely unrelated email regarding the minutes of a meeting with toxicologists. This does not appear to be part of the email chain discussing Henderson’s report.)

Henderson then informed Cekovic that he had “dropped” the report at the DRA. The DRA is referred to in multiple OPCW documents as “Documents, Registration and Archiving” and appears to be some kind of service that carries out these functions. Henderson claims he dropped off the document on February 28, 2019 at a quarter to three in the afternoon, the day before the final FFM report was due to be published. This would not have given the FFM or other stakeholders sufficient time to assess it before the publication of the final FFM report on March 1. As we have seen, Henderson’s report appears to have come as a surprise to others within the OPCW. 

Once brought to his attention, Braha asked why Henderson had placed such a sensitive report in the DRA and asked for it to be removed. Although some have attempted to portray this as a cover-up, Braha’s motivations seem clear: the Douma investigation is a “non-routine mission”, and the DRA was not supposed to hold those kinds of documents. 

Email from Mr Braha dated February 28, 2019, from an email chain regarding Henderson’s report. 

Henderson’s Report

So far, the only documentation which has been published regarding the findings of Henderson’s “engineering sub-team” has been this report, which is a summary document: it does not include the simulation or large amounts of the data associated with the simulation. Indeed, even the technical drawings in both versions of his leaked report are too low quality to read properly. This makes it very difficult to assess the simulation itself.

However, we can look at the data and information that Henderson fed into this simulation and compare it against what we know about the Douma attack and previous examples of chemical weapons usage in Syria. Once we do this, it becomes clear that Henderson has based this entire simulation on one major assumption and several errors. Although his simulation may be accurate with the data provided, a simulation based on an assumption is unlikely to return reliable results. 

The major assumption which potentially influences Henderson’s analysis was that the cylinders could not have fallen from an altitude of less than 500m. Although helicopters do usually operate at a higher altitude in Syria, it is entirely possible this helicopter was deliberately flying lower than 500m.  

Although a low-flying helicopter puts it within range of small arms, it can also make it more difficult to target, especially if it were deployed at night, as was the case in Douma. There are circumstances which may have led to this helicopter flying below 500m, and Henderson’s decision to exclude that as a possibility is based not on evidence, but assumption.

Indeed, Henderson explicitly says in the hypotheses section of the report that these cylinders should be considered to have fallen from an “unknown altitude”. By arbitrarily setting the minimum altitude to 500 meters for his simulation, Henderson is not only introducing a fundamental assumption into his analysis, he is not even testing his stated hypothesis in the simulation.

Extracts from Henderson’s hypotheses

Due to a network of plane-spotters who operate in the ground in Syria, we even know there were reports of two Mi-8 Hip helicopters taking off from Dumayr airbase, followed by two of the same kind of helicopters above Douma at the rough time this attack took place.

Graphic from the New York Times Visual Investigations Team investigation into Douma

Analysis Of Location 2

Henderson’s assessment about Location 2 is flawed from the outset by the assumed minimum altitude at which the cylinder dropped. Bizarrely, the report does in fact state it was possible to simulate an impact that was consistent with Location 2, but that the velocity was significantly lower than cylinders dropped from 500 m or higher. 

Extract from Henderson’s report

The report also appears to dismiss other circumstances that could have affected the impact. For example, the report does consider the possibility of an “intermediate impact” with the corner of the terrace wall. However, this scenario was dismissed due to lack of observed damage on the rest of the cylinder, as well as the perception that this intermediate impact would not have been consistent with the secondary impact that created the crater. It is not made clear in the report whether Henderson actually simulated this scenario or not. 

Extract from Henderson’s report

It should be noted that the final FFM report did simulate this scenario and the damage to the cylinder did appear to be consistent with an intermediate impact.

Extract from final FFM report

Henderson also dismisses the idea that the cylinder was fitted with the framework found on the roof.

Extract from Henderson’s report

However, Forensic Architecture recreated this framework and identified that the mild steel framework not only fits onto the munition perfectly, but is also almost identical to that seen at Location 4, and indeed many other examples of chlorine munitions used in Syria. This framework being attached to the cylinder was entirely consistent with the hypothesise that Henderson was supposedly testing, yet he chose to ignore it. 

Forensic Architecture recreation of the framework.

Henderson’s statement that the cylinder did not appear to have been fitted with the framework is also odd: no example we have identified of this kind of framework appears to be bolted, welded or otherwise physically attached to the cylinder. Rather, the framework is held on by the tension of the securing bands, leaving no obvious trace on the cylinder itself. Henderson’s decision to simply discount this framework is not supported by what we know about this kind of munition. 

Henderson also states that the crater on the balcony at Location 2 is “more consistent with that expected as a result of blast/energetics (for example from a HE mortar or rocket artillery round)”. In support of this he mentions several points: the way the rebar in the roof has deformed, a crater of similar appearance on a roof close to the balcony (which he does not confirm was created by a blast), an “unusually elevated, but possible” fragmentation pattern, indications of concrete spalling and black scorching underneath the crater.

The final FFM report directly disagrees with these findings. They also considered the possibility that the crater was a result of an explosive device, but concluded that it was “unlikely given the absence of primary and secondary fragmentation characteristic of an explosion”. We also know that the scorching under the crater was likely not from an explosion: the final FFM report includes an interview where a witness states that the black scorching underneath the crater was as a result of someone lighting a fire in the room in a crude attempt to decontaminate it.

Analysis Of Location 4

Henderson included a graphic in his report that showed the cylinder at Location 4 overlaid on the hole in the roof. Although this was included for “illustrative purposes”, the manner in which it has been placed, with the front of the cylinder jutting out over the hole, appears to support Henderson’s claims that this cylinder could not have passed through this hole with the “valve still intact… and the fins deformed in the manner observed”.

 Extract from final FFM report

Bellingcat and Forensic Architecture worked together to re-create the cylinders based on dimensions found in various OPCW reports. The final FFM report noted the height of both cylinders found at Douma to be 1.4 m. They also noted the width of the cylinder at location to be 0.35 m. Additionally, the final FFM report reported the dimensions of the hole in the roof to be 1.66 x 1.05 m. We assessed these measurements and noticed that the cylinder used in the image above appears to be approximately 8 cm too long, a notable difference in the stated measurements.

It is also notable that Henderson used an image of the cylinder post-deformation to “illustrate” his work, when it is much more informative to compare the pre-deformed cylinder to the hole. In short, this “illustration” is unsuited to show the cylinder in relation to the hole. Its format in the report is potentially misleading. 

We can also call into question Henderson’s statement that “The observed deformation… were clearly consistent with a cylinder having impacted in a flat configuration on a horizontal surface, and not that of a cylinder having penetrated through a crater.”

Images of the cylinders with their framework clearly show that the fins have been bent in a manner that suggest it has passed through a gap, while at least one of the securing bands has ruptured in a way that indicates it was pulled apart, which could have been the case if the cylinder had passed through a hole in the roof.

Bottom: Location 4. Note the manner in which the rear-most securing band has ruptured and deformed. The top image is an example of a virtually identical munition found in Aleppo in 2017.

Note the deformation of the strut, marked in red, and of the securing band. 

Although Henderson noticed the heavy corrosion on the cylinder, he states that this corrosion would “most likely not have degraded to such an extent in the case of it being inside the bedroom” and that it seem unlikely that such an “old, rusty, already damaged cylinder” would be deployed from an aircraft. 

The implication of this is that the cylinder has been recycled from another attack, indicating a “false flag”. However, in Part 1 of this series we demonstrated without doubt that the framework of this cylinder was initially clean and un-corroded. The rapid corrosion was almost certainly as a result of the metal having come into contact with chlorine gas, which results in rapid corrosion.

1: Still from video by Forensic Architecture, 2: Still from video by Forensic Architecture, 3: Image taken on 8th or 9th April, 4: image from Russian news report aired on 26th April, 5: image of cylinder in FFM final report, 6: image of cylinder in Final FFM report after tagging, indicating it was taken on the 3rd June 2018.

The Methodology

The report’s methodology describes how an attempt was made to create two clear opposing hypotheses which were then tested against each other. The problem with this methodology is that Henderson didn’t actually apply it properly. 

We have already seen that Henderson did not even simulate his stated hypotheses. Instead, he arbitrarily set the minimum altitude from which these cylinders could have fallen at 500 m. It is also evident that although Henderson has examined the impact of the cylinders in detail, he does not appear to make any attempt to examine the actual likelihood of the cylinders having been placed manually.

Indeed, the report provides no actual information directly supporting the hypothesis that the cylinders were been placed manually: it only provides information that might detract from the likelihood of the cylinders falling from height. Comparing two scenarios and deciding one is unlikely does not necessarily make the other more likely. 

Needless to say, this is a major oversight. The reality is that the circumstances which would lead to the cylinders having been placed manually (thereby implying the attack was faked), are extremely complex. Any analysis of how the cylinders reached their positions must take this into account. 

As such, we decided to complete Henderson’s analysis for him. Part 3 of this series will examine all we know about this event and identify what exactly it would take for the Douma attack to have been faked.


Ultimately, Henderson’s report is flawed from the outset by a major assumption which undermines the validity of his simulation. Trust in his report’s findings are not reinforced by the implication that it was written without proper authorisation, by someone the OPCW did not regard as being part of the FFM. Henderson then attempted to submit this report, which appears to have been unexpected, outside of protocol, and without time for anyone to reasonably review it. This document then appears to have been leaked shortly afterwards.

Henderson’s assumption that a helicopter could not have operated under 500m is a major assumption upon which he bases his simulation. There is no direct evidence about the height that these cylinders were dropped, yet Henderson arbitrarily decided it could not have been under 500m. 

Despite Henderson including a seemingly rational methodology, it is completely inadequate for this task. In this situation, the question of how the cylinders reached their locations cannot be rid of context — attempting to do so is misleading. At no point does Henderson consider in detail what it would mean for the cylinders to have been placed manually. Indeed he does not touch on that hypothesis until the conclusion, where he decides that it is in fact the most likely scenario.

Finally, there is the elephant in the room. The fact the FFM carried out three independent engineering analyses, by three independent teams, all of which contradict Henderson’s findings.

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  1. LibertyRising

    Great obfuscation here, thanks to for leading us to this smear job. One off-topic question: why does bellingcat ask for donations? To disguise the fact that they are supported by our government via grants from the National Endowment for Democracy? Thanks to for calling out this U.S. propaganda tool and their resultant lack of any credibility.

    • Rob

      Sure, Igor.
      Just try and debunk any of the facts that Bellingcat presented here.

      Or explain why your friend Ian Henderson claims that a 1.4 m long cylinder could NOT possibly fit through a 1.66 m wide hole.

    • Servus

      Great you found the site that matches your opinions and tells you what to think.

      Your insistance on the fact that Bellingcat gets financial support from democracy endorsing organisations shows rather typical mentality of Russian trolls or genuine conspiration theories infected mind. Russians live in a society where the organizing principle is corruption.
      The trolls are also the best example of it; they can say anything if their paymasters demand it.
      The idea that one can support an independent journalistic organisation without demanding an editorial line in exchange is for Russian trolls’ mind outside their cognitive envelope.

      I have read your site’s article about OPCW leaks and it’s what I expected, a well meaning intelligent person tries to make sense if pieces of internal communications, something not possible if you don’t know the organisation’s context or details of the FFM processes.
      It is simply naive to think that one can just step in and explain everything .
      And, when author does not understand something then its a signe of a ´conspiracy’. Its an easy and lazy type of journalism.

      Example, the phrase about removing Henderson’s report from a general document store is for him a sign of cover up. While even the mail explains that the FFM documents have different security classification, not supposed to be stored in general store, a dull procedural requirement.
      Thus he fails also to deduce that at this stage Henderson did not know FFM procedures and did not have access to the FFM’s secure server, thus was not member of the FFM team.

      Bellingcat articles give the background information , with source references, you can verify most of the facts for yourself.

      If you have any concrete objection to the article, don’t hesitate to share it.

      • Dave DeCamp

        Hi, I am the author of the OPCW stories on My pieces do not tell anybody what to think, they just present the facts. The only opinion I really add is on the media blackout.

        Ian Henderson was a long-time OPCW employee and has more knowledge of the inner workings of that organization than bellingcat does. While your investigators may have more insider knowledge than I do on the organization, the attempt to smear Henderson’s character is shameful. There is a reason he is speaking out, and OPCW management needs to explain what is going on here.

        Also, pointing out that bellingcat receives grants from an organization funded by the US govt is no different than pointing out groups that are funded by the Russian govt.

        Here is Peter Hitchens rebuttal of this story:

        • Servus

          Thanks for contributing, will find a moment for a more complete answer.
          (but I’m just a reader not a BC journalist).

          • Servus

            “Also, pointing out that bellingcat receives grants from an organization funded by the US govt is no different than pointing out groups that are funded by the Russian govt. ”

            Dear David,
            last and funny one, please help me understand this strange phenomenon :

            People getting US government grants say that publicly at their web sites.

            Organisations and people getting Russian government (often not directly) money, hide the fact.
            And when cough lying about it, may return money or find laborious explanations.
            Why getting money from Russian state kills your reputation?
            IMHO it should , is anti-war getting Russian state grants or Russian oligarchs’ ?

        • Servus

          you say that BC article is an “shameful attempt to smear Henderson’s character “.
          So, I reread the article trying to imagine how I would react to its content if I was Ian Henderson. Would I feel offended, would I see character assassination attempts, insults, or disagreements with my work and methods.

          Sincerely, I did not find any direct attempt to make a value judgement of Ian Henderson’s person, skills or motives. I could have missed something so please, tell me and I could change my mind and apologise.
          The only area where Mr Henderson could feel that incorrect information is passed about his person is about his relation to OPCW but BC makes it clear where it gets its information from (mostly leaked mails) and what are the white spots.
          Then of course there will be many technical disagreements, Mr Henderson may feel that some parts of his executive summary were not properly understood because of its summary nature. Technical disagreements could be resolved with the detailed report and recreation of the simulations with an independent team, as it’s usual in the scientific context.
          I would be red faced and didn’t feel well when BC points out basic methodological error that makes the conclusions invalid. Not wrong or right but of unknown reliability. This is basic logic, false reasoning based on true propositions results in conclusions that can not be trusted.
          When comparing two alternatives, one cannot say that N2 is more likely, if a problem is encountered with N1 but N2 is not analysed at all. There is no mention either of any such further analysis in the detailed report.
          But just to tell you where I’m coming from, here is how I read the report for the first time.
          I have big respect for OPCW, its work and Mr Henderson, they do work to make the world a safer place, often risking their lives in war zones and handling very dangerous substances.

          I’ve seen the report early on before any articles so, I was unbiased as a human can be, with a positive attitude to OPCW and Mr Henderson, expecting a nice technical treat.
          BUT already one opening phrase cough my eye, page 1, point 3 :
          “an engineering assessment has been conducted , using all available information, to evaluate possible means by which these two cylinders arrived at their respective locations as observed.”
          This “mission statement” is clearly outside OPCW FFM stated and funded effort. So I was surprised and confused, I simply did not understand it.
          This alone makes this document strange and indicates a strong suspicion that it is not commissioned by the OPCW.
          The best explanation of the OPCW’s mandate is given in an OPCW answer to Russian letter from 26/4/2019 (long but worth reading).

          Answer 8.1:
          The analyses of the FFM are based on the facts and data collected and corroborated by the team and not on assumptions. In this context, the FFM report on the Douma incident does not contain assumptions or statements about the use of a helicopter (or any other craft) and the height of flight. The report does not provide information outside of the mandate and methodology of the FFM. Regarding the ballistics analysis, the methodology of the FFM is
          based on the collection of information and facts in relation to the physical measurements and properties:
          (a) dimensions, damage, ruptures, deformations, and other characteristics of objects at the locations (walls, ceilings, windows, furniture, etc.);
          (b) dimensions, damage, deformations, specific angles, and other characteristics of devices (cylinder(s) in the case of Douma, and munitions or other devices in other cases);
          (c) photographs and videos taken at the site of an alleged incident;
          (d) sample collection of different materials (besides looking for proof of toxic chemical exposure) looking for consistency/density/physical characteristics of different objects (walls, ceiling, furniture, various fragments etc.).

          Based on these facts, modelling from physical measurements on site with reverse scientific calculations is used to determine the range of force, velocities, and trajectories possible for the cylinder to have caused the damage observed at the site. The FFM does not base its modelling or calculations on assumptions about the height from which the cylinder could
          have been dropped or the height of an aircraft. Therefore, in accordance with its mandate, the FFM did not comment on the possible altitudes of aircraft in any assumed operation modality.

          So I read on, without really deep analysis of details, one or to things caught my eye and I started making some calculations and verifications, but with no major objections or questions. The whole report was based on simulated fall from 500m, something I understood was not corresponding to the FFM simulations, so this was an open question for me . But not too important, that sort of technical issues get always sorted out in the end.
          Then came atomic bomb, obvious methodological error, I was terrified, I simply could not understand how this could happen.
          So I tried to find explanations, maybe second hypothesis was taken care of in the detailed report, well the executive summary did not mention it but should have so… Then I thought that, as it’s often with leaked documents, it must have been a draft, not yet reviewed, any reviewer would catch it and correct the conclusion to something like “the airdropped hypothesis has serous issues”, or “alternative explanations should be sought” , anything more in line with the findings….
          Then BC article confirmed that this was a final executive summary.

          This was just to show you David that one should be a little bit more prudent with leaked technical documents and just a good journalistic skills should be complemented with some research competence. Leaks have always a purpose.

          “My pieces do not tell anybody what to think, they just present the facts. ”
          You can be that naive ! You uncritically report and comment leaked documents and thus give them credibility and your own bona fide interpretations.

          This is the way it works, all we relate is an interpretation.

          • Dave DeCamp

            Saying that Henderson’s methodology is flawed and inadequate after internal emails show him saying that he was the “most qualified” certainly is an attempt at character assassination. That’s why “Sources close to Henderson” asked peter hitchens to write that rebuttal. Those sources could be friends, family or even former colleagues within the OPCW.

            Henderson is an expert who was actually deployed to Douma. Bellingcat bloggers and anonymous commenters nitpicking his reports do not change that fact. He is more qualified.

            According to Henderson, it looks like the entire team that was deployed to Douma do not think a chemical attack occurred. If this is true, it is huge. Why did they make a new FFM that only deployed to “country X?”

            These are the questions the OPCW should be answering. But there is no pressure on them since the media has been silent. That’s my point.

          • Rob

            “Saying that Henderson’s methodology is flawed and inadequate after internal emails show him saying that he was the “most qualified” certainly is an attempt at character assassination. ”

            OK. This is what Bellingcat stated :

            “Henderson’s report is fundamentally flawed by the assumption that these cylinders could not have fallen from an altitude of less than 500 meters.”

            That’s not “an attempt at character assassination”.

            That is pointing out a fundamental scientific flaw (assumption) in the way that Henderson obtained his conclusions.

          • Servus

            re : David
            “Saying that Henderson’s methodology is flawed and inadequate after internal emails show him saying that he was the “most qualified” certainly is an attempt at character assassination. ”

            The statement above has a logical flaw. I don’t doubt that Henderson was and still is a very competent person but this did not prevent him from using inadequate methodology, as pointed out by BC, and making flawed logical conclusion. Competent people make errors as well.
            Could you consult somebody knowledgeable about scientific method?


            Hypothesis H1 can be either True or False , or have unknown truth content.
            The conclusion is an XOR (exclusive OR, “either or” ) operation between (H1.xor.H2)
            Henderson says that (H1)=F
            The H2 truth status was not established so it can not be used in this xor operation or results are undefined.

            (true.xor.false)=true, H1
            (false.xor.true)=true , H2
            (false.xor.undefined)=undefined and not “H2 is true”
            (false.xor.fales)=false is the interesting case here
            Henderson says H1 is false
            BC says that H2 is false
            So, the result is that we have to go back and check why we can’t pick between the alternatives.
            And BC did just that, H1 is based on assumption about airdrop from 500m or higher.
            Later in his document Henderson says that (point 17) observed deformation and damage could be simulated with lower impact speed and different impact angle. Then in point 20 contradicts it by saying that they could match observation with simulation of all possible speeds.

            FFM final report says that three engineering teams found cylinder damages consistent with cylinders flying in with certain velocities and trajectories. We have 3 times conformed that H1 is true, that there are impact speeds and velocities compatible with observed reality.

            do you really think that pointing out a logical flaw in an argument is a “character assassination”?

        • Rob

          Dave DeCamp, you talk about this article here as “Bellingcat published a smear job on Ian Henderson.”.

          Can you substantiate your claims, and state EXACTLY where Bellingcat did any type of “smearing” in this piece right here ?

          Here at Bellingcat, also in the comment section, we want to use fact based and ‘open source journalism’ : We are more interested on how and why Henderson cannot possibly fit a 1.4 meter cylinder through a 1.66 meter hole than about Henderson’s credentials or his “knowledge of the inner workings of that organization [OPCW]” or his funding.

          Can you tell why Henderson cannot fit a 1.4 meter cylinder through a 1.66 meter hole ?

        • SM

          BC is cleary a non neutral organization, so don’t be surprised. They ALWAYS put shit to Russia side, and therefore comments are populated by Putin/Russia haters. Of course, BC is a useful tool for ‘western propaganda/democracy’ and i would really know how they got a lot of infos, i’d bet atleast 1 euro that they are deeply linked with some ‘services’ not well described, of course, in BC reports.

    • Clay Claiborne has a long history of supporting Assad’s CW attacks. Read what they wrote the day Assad slaughtered over 1400 with sarin in Ghouta 21 August 2013:
      “Syrian Rebels Claim Hundreds Killed in Chemical Weapons Attack
      Officials Deny Allegation
      by Jason Ditz, August 21, 2013
      Oddly timely since the UN chemical weapons experts arrived in the nation just days ago, Syrian rebels are now claiming a sudden massive chemical weapons attack on the outskirts of Damascus, saying 213 people were killed in a nerve gas strike on Ghouta. Other rebels claimed 635 had died.”

    • Toby

      So you’re using a nutcase conspiracy site that frequently supports #terrorussia as evidence that a well respected investigation site is somehow untrustworthy?

      Wow. The lack of critical thinking involved in your post is breathtaking. The only things lacking credibility here are you and your joke lie site.

      • SM

        Well respected by whom? Wikipedia, as example.

        BC = just propaganda vs Russia. Not really important if they find truth or not, states always lie if they feel good to do it. But with all the shit done by western countries, BC seems not really care much. All the evil is in Moscow and Damascus, of course.

  2. Adam Larson

    Servus, yes OPCW-verified sarin in attacks on soldiers. How far do you need your hand held? The reports are linked at the posts I linked, and the details of the OPCW findings are in those. At least the three cases directly verified. GPPI lists one as a sarin attack, and according to OPCW the soldiers were the only ones involved and with sarin in their blood. They wouldn’t say it sarin got there, if the soldiers’ story was true or not, but no reason to doubt the stories was given (they claim to not be allowed to believe or disbelieve). And Khan al-Assal is now said to involve sarin.

          • Adam Larson

            the links do not meet your criteria WHY? The OPCW-derived information is IN those reports, and AFAIK there’s no more SPECIFICALLY OPCW reports that were made public. So you can ignore the information as never coming from that exactly defined kind of report never made public. Right? Or, what else? Wasting my time? No, that was MY stupid choice. So just keep demanding whatever to avoid learning. I won’t answer.

          • Servus

            So, you can’t find OPCW public document on the OPCW site ?

            Reference to an OPCW document please

            You made a unusual claim so please substantiate it.

          • Adam Larson

            JPT – so you couldn’t reference an OPCW document either, huh? Too bad there’s just so little around for these guys to learn from. I mean, Servus was all ready to check the text to see how I misread it, but then there was nothing to check, so I guess I’m just plain Russian troll. And you too, apparently.

          • Rob

            Adam, regarding this document you posted as evidence for your assertion that Syrian soldiers were targeted with chemical weapons :

            I just started reading through this document, so please help me out here :

            What I see in that OPCW report (page 5) is a reference to “ALLEGED INCIDENTS IN NOTE VERBALE 150” that supposedly harmed Syrian Army soldiers.

            But just above that we read :

            “the Secretariat received a note verbale from the Syrian Arab Republic (reference number 150, dated 15 December 2014, hereinafter “Note Verbale 150”) providing information about incidents involving the possible use of chemicals as a weapon..”

            So the allegation that Syrian soldiers were harmed by chemicals came not from the OPCW, but from the Syrian government.

            OPCW then acted :

            “Upon receipt of Note Verbale 150, and due to the severity of the allegations, the Director-General decided to dispatch a team to the Syrian Arab Republic to collect the facts pertinent to incidents as reported in Note Verbale 150. ”

            They interviewed witnesses and medical personnel, and alleged victims.

            However there is this in the summary for the Jober incident for example :

            “The FFM was not able to identify a cohesive narrative based on the testimonies of these particular casualties. Additionally, the FFM could not corroborate this narrative with the prevailing narrative established by the analysis of the testimonies from the bulk of interviewees. ”

            Other incidents seem much of the same : no evidence that Syrian soldiers were subjected to any chemicals, and no consistent narrative of the people interviewed (note that all these people interviewed were under Syrian government control).

            I have not gone through the entire document, so if you could point out which page(s) contain evidence for your argument that Syrian soldiers were gassed by opposition groups, that would be nice.

            Thanks !

          • Adam Larson

            back on a whim and some one noticed reality. Huh. Good job Rob.

            OPCW never originates allegations. Others do, they come look. Always. If the SAA were attacked, who else SHOULD have reported it? This pat is like it should be. And they even came and looked.

            Other questions were answered at the start with a few links servus didn’t like, wanted original reports instead, not some kind of summary with pointers. (didn’t want the reports either)
            24/25-8-13, Jobar, Daraya:
            29-8-14 Jobar:
            15-2-15, Daraya:

            Not reconstructing the quotes, page numbers, notes etc. here. It was gathered for a reason.

            The FFM got confused about THE narrative of 29-8-14 because it was TWO incidents reported and they decided it should be one, apparently. Not sure if that’s the one you mean. If so, open to other readings.

            OPCW accepted exposure to some chemical in each case, just tried to cast it as random, harmless, not a weapon, not their area. I argue for 29-8-14 they did this poorly (as an example they spent unusual effort on – others appear similar but lower-key in their dismissiveness).

            Even in the verified sarin cases (other 2 links) OPCW won’t say HOW the sarin got in the soldiers’ blood, if it was an attack or what. The Bellingcat way of course: presume false-flag, gassing their own, and OPCW was more than fair to this state party to the CWC, considering.

  3. SgCloud

    The new article published by Peter Hitchens (
    might induce a need for a correction in the article. I’m having in mind the passage in which BC deduces that Henderson was able to simulate a scenario under 500m that made it possible to explain the deformations in the cylinder. He wasn’t, it was just a conclusion drawn from a non-specified “analysis”.
    It feels like we won’t get to have an progress in the matter unless we are able to take a look at what kind of models were used in assessing the damage observed in the roof and in the cylinder and how they hold up to each other.

    • Servus

      Henderson’s report is a summary with no full details.
      But his text says explicitly that helicopters are assumed to fly somewhere between 500 and 2000m,
      In a drawing or a photo there is a mention of deformation with impact velocity of 100 m/sec and this corresponds to a terminal speed of a ´back of the envelope ´ calculation for a free fall in vacuum from 500m.
      And its logical, Henderson tests fall from the lowest height in his assumptions and finds that such fall should have created a bigger building damages. This is correct conclusion, but 500 min height limit does not need to be true.

      If you look carefully at the FA drawings in the FFM final report, you can find information about impact velocity that matches the building damages .
      I don’t remember the exact value but it was less then 100m/sec so one could think that the fall height was lower.
      But here personally I would refrain from further guesswork, we have a 3 dimensional fall with two velocity vectors , I have no intuition for such situations.

      • SgCloud

        Hey Servus,
        the way I understand Henderson’s report after reading the article in Hitchen’s blog Henderson only initially assumed a drop altitude higher than 500m while later expanding the scenario to all possible velocities and thus, to all possible heights. Even then he wasn’t able to arrive at an outcome that should the deformations observed at location 2.
        Of course I can’t judge how good his simulations were given that, as you correctly note, there are no details given. We also don’t have a whole lot of info on how the OPCW-requested simulations arrived at their conclusions. So I think we are in need of more transparency in this regard to arrive at a proper conclusion on whether the observed deformations speak against a helicopter from a helicopter.

        • Servus

          Hi SgCloud,

          I respectfully disagree about the “initial”.
          To support his conclusions, Henderson presents the result of a simulation in appendix A. at the pic 1, one can read a text:
          ” Figure 26 Final frame simulation of the impact of a vessel with an initial velocity of 100 m/s (a) complete model and (b) visualisation without concrete”.
          Henderson’s report page 6 point 22 compares predicted deformation with the drop height of 500m and observed cylinder deformations and concludes these don’t match.
          The “500m” is mentioned at several places talking about simulations.

          Appendix A is entitled : “L2 predicted and observed deformation”

          So, even if section “Methodology – Location 2 study” does not explicitly reference appendix A, it’s obvious that it demonstrates discussion of it,
          specifically in point 13 (visualisation of bars impact).
          And point 22; predicted cylinder deformation (picture 1 & 2) not consistent with observed actual deformation (picture 3), predicted results are more consistent with other deformation examples (picture 4 & 5).

          So to visually support his conclusions, Henderson uses pictures with simulation of impact velocity (called ‘initial’ because the terminal will be 0) of 100 m/s which corresponds to terminal velocity of a free fall in vacuum from 500 m height.
          So, Henderson conclusion point 32 says that “we can not be certain that cylinders arrived there as a result of being dropped from the aircraft” and point 33, “the alternative hypothesis produced the only plausible explanation”
          is apparently based and justified mainly on simulation with a drop heigh of 500m or 100m/s.

          Henderson’s “initial assumption of 500m” was also the only one used in his report, as I said before, it’s logical within “500-200m” hard limits, the least energetic case was already too much if compared with the actual damage.

          ” SgCloud – January 26, 2020
          the way I understand Henderson’s report after reading the article in Hitchen’s blog Henderson only initially assumed a drop altitude higher than 500m while later expanding the scenario to all possible velocities and thus, to all possible heights. Even then he wasn’t able to arrive at an outcome that should the deformations observed at location 2.”

          I don’ disagree, this is the meaning of the point 20 page 5.
          What it say is “we were not able to simulate the cylinder and building damage at any impact speed”, this is incredibly strong statement. So why isn’t it No 1 finding for both locations ? Why is the whole comparison done with a fall from 500m, that in my ‘back of the envelope’ type calculation is roughly 3 times as energetic as the observed damage would cater for ? Making simulation with 3 times the required energy doesn’t say anything interesting or they failed to explain that.
          Why didn’t they pick something closer to the observed cylinder deformation and show that it was still not consistent ?
          This is really what I don’t like about this report, more you look at it, more questions you have.

          And as you say, now the teams should publish (at leat to each other) , at least martial parameters/constants used in the simulations.

          Now the Blog Post (BP).=, point about 500m assumption.
          The staring point 500-2000m is fine with me. There is some interesting information about the simulation team, ok, fine.
          Now tricky part, explanation why 500m was chosen. Basically they say pilots would otherwise have been taking unreasonable risks, but what if they did?
          Second guessing somebody this way is prone to what I call”me” or “projection fallacy”. We project our rationality, ethics and knowledge, whatever, on some other person and then conclude something about their possible behaviour. Works more or less OK for your family, friends or people from your cultural circle. But it’s prone to gross errors, for example, I can not imagine mentality of a man beating his wife to death, so it does not happen, right? So second guessing behaviour of unknown war criminals from unfamiliar culture is a rather delicate proposition.

          Without much emphasis due to my incompetence in the matter, is flying a helicopter below 500 m at night, over a completely dark city (no electricity) that dangerous ? Anybody shooting at it would disclose it’s position and risk a back fire. Helicopters did not hoover, the cylinders had a horizontal velocity component as well (according to FFM final report).

          Last questions in the BP, “would BC be satisfied if all simulation results were published and showed no match with reality ?
          I can not answer for BC but myself. Yes, it would be very useful but not enough. Just like for ANY other scientifical study, this results are provisional unless verified and confirmed by other independent scientist. So, publish parameters please and why not the code to competent teams (with an NDA agreement).

          BUT… wait a sec…was this not done already ? OPCW FFM final and OPCW answer to Russian and Syrian questions stated clearly, 3 different independent teams have confirmed results documented in the FFM Report.
          And found that damage to the cylinders and buildings are consistent, they were supposed to work backswords, from the observed deformations and building damage, deducing trajectory and initial impact velocity. FFM final does not document this velocity but it can be deduced from one of the simulation diagrams.

          So it’s not over yet, but I’m confident that, over time, all questions will be answered .

          • Servus

            rereading the BC report I find a following contradiction in the Henderson’s report.
            Location 2 analysis Point 17, at the end :
            “Analysis of the evolution of the vessel deformation during the penetration of the concrete showed the vessel shaped observed in the observed (aligned impact) event could only have been caused by an impact, under 20°, with initial velocities significantly lower then the ones considered in the simulations.”

            and the point 20 “we could not simulate the reality with any set of speeds”.

            The point 17 text points to an agreement with what is documented in the FFM final report, the appendix with the simulation graphs. And suggests that lower speeds were not simulated so what is the origin of the text in the 17, not a simulation with lower speed ?

            again…look deeper, more questions

  4. iraqi origin

    there is zero trust in the americans and the british, bellingcat purpose is to defend terrorists such as isis and alqaida, the second purpose is to defend the americans and the british parasitic intelligence services such as the cia and mi6, these agencies are worse than hitlers ss, that should give you a picture of what kind of parasites they are

    bellingcat just leave middleeast, go and parasite on your own people

  5. SorryViennese

    Dear Bellingcat journalists.
    Were can I find the 3 Henderson-independent engineering reports, you mentioned, at least at the Business Summary level, as the (Wiki-)leaked FFM report of Henderson is?
    Can you provide me with a link to that 3?

    KR, SV

    • ZigZagWanderer

      Yes .. the article makes no excuses for being a hatchet job on Henderson and makes repeated reference to these 3 reports that discredit Henderson’s report.

      I too was wondering where to find them. I’d like to read them.

      8 days and no reply from BC ….. I wonder why ?

      • SorryViennese

        Dear ZigZagWanderer,

        as of now, and at least after 5 requests on BC report 2, 3, and 4 comments sites by me and others:
        Nobody came up, they are not public, their names are not known.

        So the conclusion has to be: They do not exist, they are just claimed.
        No Experts, nor their reports are public.

        Even the Ambassador of Britian to the UNSC mentioned those 3 as important, at the recent ARRIA meeting, but did not name them.

        If they are not produced within 5 days, and they defend in public in front of an cricitcal ballistic expert pannel, e.g. the ballistic situation at Location 4, then they do not exist.

        KR SV

        • Paul

          They are in the report which is linked at the top of all of these articles:

          ANNEX 12
          Page 104
          The FFM requested three independent analyses from experts recognised by their
          respective institutions and the international community for their knowledge, skills,
          and experience.

          The independent analyses results were complementary and, as such, presented in the
          main body of the report.

          Unless you’re going to hold Henderson to the same standard and ask for more than an executive summary of his report, you’re just blowing smoke.

  6. ZigZagWanderer

    Dear Bellingcat Investigative Team .. have you no names ?

    Anyway .. you consider yourself the leading authority on the Douma / OPCW/ Henderson affair.
    Why have you not mentioned this from Sebastian Braha Chief of Cabinet at OPCW ?

    “Please get this document out of DRA [Documents Registry Archive] … And please remove all traces, if any, of its delivery/storage/whatever in DRA,” the leaked document reads.

  7. JustPassingThrough

    The Forensic Architecture video shows you have also got the hole wrong – this is not true

    166×105 is the *outer* measurement of the damage as shown by the black box in the FFM report A.7.6 image (and Henderson’s scale drawing). The Bellingcat cylinder, fins and hole are all wrong. Are you going to fix your measurement errors?

    • SM

      No, go figure. Wikipedia.en is believing to BC and this is all what matters. People need to be acculturated to the Washington Truth.


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