Douma CW Massacre: The "CW Barrel Bomb" That Wasn't There

Alleged Chemical Attack in Douma, April 7, 2018:
The "CW Barrel Bomb" That Wasn't There
(rough, incomplete)
April 14, 2018
edits/updates 4/16, 4/17, 4/21+22...
big updates May 6

So now president Donald Trump has attacked Syria for a second time, based on accepted claims of an illogical chemical weapons attack by the Syrian government. Some people, if not the bulk of the Western public, will wonder how firmly this decision was based in fact. 

This time the story was lodged in Douma, Damascus east Ghouta suburbs, on the night of April 7, as victory for the Syrian army was only held up by some strange delays by the ruling Islamists. Jaish al-Islam refused full surrender, then launched provocative artillery attacks on Damascus, prompting alleged counter-strikes including the destruction of a hospital, and two chemical attacks. JaI fully surrendered the next day after getting this story lodged before the world as what supposedly finally broke their will. Some more thinking may be in order on how this all adds up.

The apparently desperate act was first reported as a chlorine gas attack, and everyone agrees that's what they smelled. But the death toll was always too high, seemed to sudden (judging by the way they were piled up, like they were all crowded together and dropped suddenly, or just tossed in piles...). There were enormous amounts of foam from the victims' mouths and noses, which 'everyone knows' is caused by pretty much any chemical weapon. But miosis was reported, and secondary contamination...

Soon opposition groups and western agencies and governments had concluded there was an unidentified nerve agent mixed with the chlorine. In the age of sudden "Novichok fears," for some reason they won't specify sarin like usual. They claim it came from a "barrel bomb" as they call it, or a slightly modified chlorine gas cylinder, 44-liter, as allegedly used by the government before since 2014 to deliver chlorine gas. One was said to be dropped from a helicopter to fall on an apartment building, killing dozens. Maybe others landed somewhere else, affecting hundreds (700-1,000 total, including an earlier attack with just chlorine). 35-40 up to 85, over 100, 150, and even 180 have been reported or estimated to have died from the chemical. (this is basics overview - sources and details on all that elsewhere).

So far two related munitions have been shown. The first one we saw came in a bizarre scene covered for now at the main article, to be refined and moved sometime. The second one we were shown is more interesting and of clearer (alleged) relevance - it was seemingly directly above the 30 or so people found dead and shown widely on the Internet. But as I'll show, it seems:'
- the thing wasn't there when its alleged impact occurred before April 7
- it was likely there but seeming staged atop prior damage on the night of the alleged attack
- it remained a strangely intermittent piece of evidence thereafter.

The When and Where

The location is somewhat disputed. Open-source investigator/propagandists, Bellingcat picked a spot for their analysis. The opposition Violations Documentation Center (VDC) gave a different spot in their report, but seems to have just marked the mosque it was reportedly near; they didn't have an exact location. That's odd, as the VDC is, or was originally, based right in Douma. This image uses their graphic, with Bellincat's spot added, and notes. 

Michael Kobs for a moment thought the scenery matched the spot VDC gave, but it doesn't really, I think we all agree now. (see comparison images here and note Kobs had somewhat led the public investigation of this incident, generally very well but with this one error anyway) I'm not sure, but the Bellingcat spots seems like a good  fit. 

Wherever it is, the site visited by the oddly victorious Russians on April 9 is the same that held the bodies (see comparisons at Bellingcat). They and Kobs agree on where the gas cylinder is seen, at least roughly, from the view to the north. I didn't bother verifying that part. Whether the tank is on that same roof and truly above all those bodies is less clear, but seems most likely to me. The relevance of the following rests on that connection, so any doubts will merit some further attention.

Two Views of the Gas Cylinder
So here's the canister, most common view from a White Helmets tweet of April 10:

The cameraman shows a phone with the time 7:02 pm given in Eastern Arabic numerals (and Araic letter m for PM). The video is clearly filmed at about that time - it's visibly just after sunset, and that was 6:59, according to the NOAA solar calculator. The date is less clear in itself, and it could be on the 8th, but I see no good reason to doubt that it's the 9th. The logic of showing it and the time and place is strongest after the Russian visit of that day, where the Russians denied seeing it, or where the activists expected them to announce that. 

From the start we can see this tank has no collar to hold the fins so it falls right, as we see with the first tank that landed on a bed. Maybe it fell off? It still seems to have come in nose-down like it's supposed to. It allegedly punched a hole about big enough to pass though, but then strangely it just came to rest there. There's an odd dark color at the front, with an angle that seems like a clue. In the presence of chlorine gas, these tanks seem to rust corrosively, but this doesn't appear rust colored.  I don't know of any sure cause for this blackening, but looks like perhaps smoke residue from a fire. And there are no obvious ruptures anywhere, not that we can see it very well from different angles (such tank bombs usually release the gas by splitting open crudely on impact). It's possible the curved valve end is broken and  that the cylinder released gas here. But it's also entirely possible it didn't.

Now, we also have a less-seen view of this tank filmed in full sunlight at mid-day. Here's a tweet Bellingcat founder Eliot Higgins posted (on the 9th at 0400 (Twitter time) or 3 PM in Syria). and then deleted. The right view is of canister 1, covered elsewhere. The left view is clearly a video still, but a different one (shown in full below). That video is apparently private, not released, Higgins says, for fear it could identify the guy filming, and open him to harassment (Qoppa 999). He might say that's why he deleted the tweet with one still including ... those unique shoes? But it's not an issue for the guy holding his damaged phone up to the screen in the other video? (not that he made the call to release that one - the White Helmets did, on the 10th, but didn't seem worried about the issue). Or is there a different reason he zapped this?

Michael Kobs caught this with the screen capture, and noted: "The tweet deleted by Eliot Higgins proves some serious manipulation of the chlorine cylinder. Probably this is the reason why he deleted it. Compare the deleted version to the later White Helmet version." I think this is true. White Helmets sunset video:

Higgins mid-day scene (note also a video still):

Higgins also says "I saw photos of the same scene at 6:12pm Syrian time on April 8th. Photos, not screenshots of the video." Taking that, the scene was set up on the 8th, even if this video was taken on the 9th. I'd like to see these photos someday.

But with just these two views, filmed from the same angle, we can see the cylinder has been rotated at least. There's less black coating visible and more white dust, one of the holes in the base is visible in the mid-day shot, and different rusty scratches are seen (more detailed analysis perhaps in time). Here it seems to be laid at a different overall angle too, and resting its nose end on a metal scrap as well as some intact but compressed rebar inside, and an intact edge of the hole. Is this accident of junk what kept it from falling in? No, clearly not.

<add 4/22>Note: there should be two holes in the base rim, opposite each other. On the early view, one is seen, about in the center. In the later view, neither hole is visible. This means the rotation between views is just about 90 degrees.<end>

Considering those points, it seems quite possible the tank was not just shifted round, but removed entirely and then put back differently in between videos. That seems all but impossible to either prove or rule out, so keep this in mind.

(side notes on times: By sun, I'd say the mid-day view is shot around 1:00 pm, as Kobs estimates with more rigor. The date isn't clear. This could be from the 9th, as it was about 3 pm there. I will tentatively presume that's the case, but it could be filmed the day before. Note how the pieces of concrete slide with the movement, a red thing is tossed in the corner and a stick atop it, etc. Such clues suggest only that the sunset video is later than the mid-day one, so not on a previous day. They could both be on the 8th, hypothetically, or on the 9th, or the mid-day video on the 8th and the sunset one on the 9th, just not vice-versa. Metal scraps move around, the blanket of unclear use might be new, etc.)

The layout, presuming same place, to help understand - the street-level entrance shon on opposition and Russian visit videos is on the south side. The canister is seen on the north balcony. For comparison, Google Earth view of 3-20-13 with the true orientation.

The south balcony seems to have an outer wall, but no roof. The north one had some kind of awning, damaged frame remaining. Below is Michael Kobs' composite from street level, including where bodies where found (note: none seen in the basement, where it's said they died - the basement is never shown):

Why Didn't the Russians Report It?

The Russian investigators did get to the site where bodies were shown, on the 9th and at a time I estimate around 2:45-3 pm from sun angles, just a couple of hours after the mid-day cylinder video (if that was filmed the same day). They report finding no sign of a chemical attack. That presumably includes nothing odd in the basement, no chemical traces detected anywhere, and no chlorine cylinder on the roof, or anywhere they looked. They videotaped the whole thing. Were they taken to the roof, or rather the north balcony? I'd like to see any video they have of this if so, and if not, how can one claim a full inspection of a supposed aerial attack site without investigating the roof? They could easily have sent a drone to inspect it as well. 

But the two video views are shown as poof the Russians were lying. They seem to show the cylinder was there at the attack time (presumed, I mean, how else would people die there?), and still there perhaps just before the Russian visit (if same day, about 2 hours before), and there after sunset on the 9th, presumably, or about 4 hours after the inspection. The Russians seems to not see it in between videos. Someone has moved it around in between videos. Conclusions to draw from that will vary, but let's get these details laid out together so we can start.

I'll propose the local activists literally removed it to trick the Russians into this 'blatant denial.' They would move it as little as possible, but to somewhere they could keep the Russians from looking. There would be hand-sized patches of dust at least wiped off.

I'll leave it to 'credible professionals' and Bellingcat et al. to propose the Russians tried to physically remove it but failed, left it there, and tried blatant denial instead. 

Project: did the Russians deny CW signs publicly prior to sunset on the 9th? If not, there's no public reason to make that 7:02 video to prove them wrong - unless they had some other reason to anticipate that they would be reporting that. Maybe they knew they had removed it after the mid-day video, and predicted the Russians would report the truth of what they saw - the stupid saps, walking right into traps. 

Late Arrival to the Crime Scene
More Views of the Gas Cylinder
<Add 4/17> New imagery was published in the last day. CBS News sees the canister, about as seen.
https://www.cbsnews.com/news/syria-inside-douma-the-site-of-apparent-chemical-attack-2018-04-16/
In better resolution, from outside and inside, Swedish TV4 also shows us more.
video 1, w/inside view https://www.tv4play.se/program/nyheterna/3967012
video 2, w/basement story https://www.tv4play.se/program/nyheterna/3966948

Comparing the TV4 interior view with the night-time view, something surprising happened. I debunked my own leading argument (at the moment).  That was the hole in the roof, looking onto some mysterious glow, with no gas cylinder jammed in to block the view. Not just me - everyone who saw this agreed.

In this longer video: https://twitter.com/amer_almohibany/status/982859028324929536

at 1:30, they reach the uppermost floor and step into a dark room - the camera pans up to  a blob of light crossed by bars looks like a hole in the roof onto ... some kind of light outside. Below is a useful enhanced composite view from Michael Kobs.

But ... Guess what? It no longer leads. There are many other points, but in need of refinement I wasted here. The old text and images are almost useless now, but remain below until I decide what to salvage, etc. New notes after the new image.

https://twitter.com/CL4Syr/status/986215986578604032

...

Notes (partial, to be improved as needed):...hate to do this, but I think the hole is bigger, the sky is seen though it and it appears black, the cylinder is there, and it's what we took for the hole to a light source that remained mysterious. Rather, this is the camera light reflecting off the tank's yellow paint, through the surface grit, apparently. It seems oddly bright, but note it matches perfectly, explaining why one part of the "hole" seems brighter than the other part, and why the difference is curve-shaped. That odd slat of metal it rests on is there. 

Basically I layered the scenes so they matched about 98%, skewing the TV4 view to fit the other (Kobs, with cleaner 'hole' added, enhanced). In the left image, the darker ring doesn't mean this is the hole, it's just more enhanced, Should fix that... But in spots, it almost marks the hole, which seems about as large then as it is now. The hanging part doesn't line up due to different perspective (cropped off here), but ceiling features do, about 98%. After that, everything just starts lining up - the rebar, the corner slat it rests on, the 'hole' and the reason one part is lighter, etc.

I was stumped and disappointed about this for a minute or two. Then excited to own the inevitable destruction of this point, instead of someone else. Note: this is the same scene we still consider pretty fake-seeming. It just existed at attack time (this to be explored in some detail in another spot). And it still gets moved around later, as shown above. It's still the "CW barrel bomb" that maybe wasn't there when the Russian investigators were let in. Separately, my original guess on hole correlation and thus angle of canister below were also wrong. It was a fair enough guess fom what I had, and the whole issue is now moot.<end 4/17>

<4/18>There are still those who think this must be a hole that just happens to be that shape, or alternately that this is a different canister, one that's cleaner, more reflective, free of scratches. But I maintain the shape of the canister, likely hole, rebar, and added slats, all are undeniable. The appearance of the cylinder is still almost bizarre - like a ghostly night vision or photo negative ffect or something. But I se too little reason they would set this up with anything other than the common yellow tanks they have all over, have used frequently, and would be blaming here. The weird glow is  probably down to surface reflectivity, light type, image processing in the camera, and possibly video editing to give us a random false lead. Or possibly another tank they swapped out later and then moved around. But it's not a small, canister-shaped hole where a larger hole and everything else we see would later be.<end 4/18>

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old text mainly deleted...

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Was it There When it Landed?
(added 4/21)
So far, two points of presence are questioned, and one of those was quickly answered 'oops, it apparently was there.' Now let's go further back in time, to when this thing first allegedly crashed into the roof.

By reports, this happened the night of the 7th, depending on your source at around 7PM, around 9PM, or even 10:22PM. The first view we get is the night video showing the not-hole in the ceiling. I'm not sure what time that is, but it and related images were online by around midnight. Various clues suggest a decent time span has passed since these people died - at least an hour, maybe 3 hours or more; it's hard to say. 

The views of the room interior are very limited. Some bits will be included for comparison. The better view is from Swiss Swedish TV4, but filmed much later - April 16 or so.
night video (see 1:35): https://twitter.com/amer_almohibany/status/982859028324929536
TV4 (first 15 seconds) https://www.tv4play.se/program/nyheterna/3967012

By this time anyway, people have laid domestic items: clothing, bagged blankets, perhaps diapers, a basket, etc. on top of the rubble. Someone has also started a fire on top of the rubble. It seems it was pretty energetic from the stains, started with lighter fluid. Allegedly, the rubble is all from that night's gas cylinder impact, so all this activity must be after that as well. How long after?

Comparing the night-of video, I can't yet correlate any of the seen objects, nor correlate where the red oriental rug gives way to rubble. But from another view, we can see the basic picture of rubble, then things laid on top, is present then, just a few hours after the alleged attack. It's possible someone came in here after the gas attack to set some things aside. But why? And why didn't they drop dead here?

<add 4/22>Michael Kobs and others with some relevant adds:

room and floor confusion: Kobs explains "There is a small room with carpet, the white brick and the gray backpack (?) before the room with the window. When you enter the window room then the pile of black ash is to the left in the corner (also seen from above through the hole. The window is the same."

https://twitter.com/MichaKobs/status/987998721685229568

gray bag, red carpet area comes before rubble area

https://twitter.com/HRIMark/status/988017218737799169

window correlation, possibly the bundle of blankets?
https://twitter.com/MichaKobs/status/988332650795544576

What I think happened: this place was hit with a projectile or small bomb some time ago. It was fairly small and heavy, probably smaller in diameter than this gas cylinder. It fully entered, bending the bar where seen, tearing the cross-bars free there, ripping that long segment of material down and to the right with its main force, and a smaller segment to the left. That doesn't happen when the object just hits it from above and then stops.

The grid of reinforcing bar was pushed down or projected shockwaves, causing the lines we see like scratches: concrete disrupted along the grid lines. The material shaken free of the rebar cage fell all over the floor, leaving that concavity in the ceiling, including the proper hole all the way though. Then later, someone placed these domestic items here for no particular reason, and started the fire, and placed the gas cylinder. The order is only partially clear.

The fire is mysterious, possibly related to the events here. Its smoke perhaps coated to ceiling and upper corners of the room, and likely caused the smoke stains we see on the portion of the cylinder right above the hole - see TV4 view below.  This would be the underside at that time, later rotated. (note the cut-off line compared to hole edge - the 'parted hair' down the middle would be the original bottom, with smoke dividing to roll up either side). The rotation seen in Higgins' deleted tweet video still is likely, but not certainly, the original position at the time.  

In the night-time video, it's hard to see if there are these smoke stains on the walls or signs of that fire. That could be added later yet, or present at the time - unclear at the moment.

So the canister was added before the fire, but not necessarily before the hole was made. If it was the impacting object as alleged, it would probably be more damaged, as well as inside the room, if it had punched that hole. And the gap in the rebar might have to be bigger. It's possible an object like this would hit and not fully penetrate, but that would not explain the flung material we see, nor the exact way this seems to have stopped.

It's not really jammed into the rebar, but resting freely on top of it, easily rotated between views as we saw above. Considering the views show from above and below, it seems the canister's nozzle end rests on one or another segment of rebar (apparently the straight one, with the other bending beneath it) and two thin, twisted slats of metal that crisscross the hole, also resting on the rebar grid. There's also a piece of the broken concrete the slid into the area, probably not part of the arrangement.

How on Earth can a flying projectile violently puncture the ceiling, and have pieces of debris suddenly get underneath it?

Clearly, these things are not part of the impact violence, but were added later. But why? It might seem like they help keep it from falling in, but it doesn't seem like It would fall in anyway, with too small a gap. The slats cover the valve so we can't see it clearly - is that why? Did they help deflect the gas more down into the room, for example? Anyway, it seems clearly set up after impact.

But oddly, those same slats there at night. Even that stray piece of concrete is already there (green). There might be something else at the time right over the nozzle area, or that might be a shadow - unclear. Did someone climb up there and prop it up like that within a couple hours, as it was spewing gas?

No. It was probably arranged like this before gas release, if there was any. The fire might cause enough heat to burst the valve and start release, for instance (depending on pressure of fill, it might stay put).  But I'm not convinved it even released any gas - it might have just been placed there full or empty, not emitting anything and just to create the impression of a CW attack.

<add 4/22>That bit of concrete marked green - it's there in post-attack videos. It's there the night of the 7th. But further above, I noted it had not slid into place in the deleted Higgins photo, only by the time of the WH video. I took those both as April 9 videos, but unless that piece slid into the hole, was later pushed back in place, and slid back again at the same angle - that's possible - that deleted photo might be from before the night-of video, from April 7 or earlier.

Michael Kobs and others with some relevant adds:

10:55 first known posting of scene photos
https://twitter.com/MichaKobs/status/987975214834376706

floor plan, first floor
https://twitter.com/MichaKobs/status/987663151230586880
(with a body noted later...)

canister 3-D
https://twitter.com/MichaKobs/status/986908965626941440
https://twitter.com/MichaKobs/status/986952981533921280

prior damage noted
https://twitter.com/ilmastoblogi/status/986150563388821505
https://twitter.com/Deus_Abscondis/status/987667873739956225
windows blown out (complicating the creep of deadly gas all the way down that stairwell, out the front door, in the other dorr, and down to the basement...)
Many circumstantial signs that the apartments here weren't inhabited. It seems deserted, if not long-deserted. But that could be a false impression.
<end 4/22>

Review (updated 4/21)

* Unknown day before April 7: damage probably caused by something other than the cylinder (it's not there yet)

* Midnight April 7/8, just after attack: cylinder seemingly there now

* Sometime April 8: cylinder there, unseen photos

* App. 1 pm April 8 or 9: video of cylinder there (seen frame)

* App. 3 pm April 9: Russian investigators visit, apparently find it not there (can we have video for that part?)

* 7:02 pm April 9 (presumed): video of cylinder there, but in a different position, rotated and angled differently

* Thereafter: so far it appears to have stayed in the second position

May 6 Updates: Fire and Frost

Upon more review, I can add these important thoughts with some ... I've come to hate this phrase ... "a hugh degree of confidence." Various closeups have emerged to clarify the valve is clearly missing. It would look like this sticking out, as the bedrest cylinder shows. How it left is a mystery. The valve assembly screws into the inner neck, so we can't see enough to say if it was snapped off in-place, popped out against the screw-thread, or manually unscrewed. That's an important question we'll come back to.

Russia 1 report notes the intact thread on the outside of the neck as suggesting the valve was manually unscrewed, but that's a red herring: this is where the protective outer cap would go. Of course that would be removed. Added note: that outer neck and the nearby metals has small, wolly fibers attached, as Russia 1's footage shows. This is almost surely from when it was grabbed to move.  The fibers are all beige colored, so not likely the same beige and red blanket seen nearby. What I'd really like to see is  a close-up like this from before it was rotated to see if it already had fibers then... (note: the wire is not connected, except by blanket fibers)

Next: I had belittle the frost explanation for that white-looking cylinder. But it seems to be the case that chlorine gas containers will frost over when the gas is released. As I gather (provisional), it's stored in the tanks as a liquid, or becomes one upon puncture, or ... and first leaks as a fluid, until the level is too low (below the leak point), at which point it boils into gas (well below room temperature) and seeps out that way. It's called auto-refrigeration, and it'll tend to happen on the underside of the container, as shown here in theory and seen somewhat in this real case, from nearby Hamouriya, not much earlier (specifics aside ,Al-Jazeera video, via Charles Wood tweet, stills shown here).

Based on that idea, the above example must be on a slight incline so the nozzle end is higher (note: this is not the same cylinder recycled for Douma). So presumably, the Douma video's bright white cylinder is that underside frost, suggesting the cylinder is releasing its contents, presumably chlorine. It's probably more than half empty at that moment, with only the underside of the angled-down front end verifiably frosted. How long has it been releasing? Not sure, but probably on the scale of (a few) hours, not minutes or days. It's a reasonable fit with the lodged story, as far as I know.

So this pans out, but there's still no way this amount of chlorine, less than one canister's worth, from that hole, would cause dozens of deaths two floors below. By itself it would cause about zero: people don't pass out and die suddenly. They cough and leave the site as fast as possible. With chlorine nerve agent mixtures ... there are too many questions to say either way.

And further, the impact damage still makes little sense. As noted, the rubble was there before the blankets and such were placed, and before the fire was set, which was clearly after the canister arrived. So it seems possible the canister made the hole, if that makes much sense (it doesn't). As noted, these items are already an the rubble before the night-of-attack video was filmed. Furthermore, hat tip to Andrew (comments), the fire was also there before they arrived.  See night video compared to later: same areas are blackened already to the left and right of the window. Layered Russia 1 footage with night video, some perspective issues I didn't fix, but basic scaling is right. Apparent smoke edged painted in for each image and compared favorably.

The flickering flames suggested by yhe edge of the smoke stains suggest the window was open, letting in a breeze to feed the fire. The only difference is the curtains on the right were there that night but have been taken down since then. This is seen on the ground later - likely torn down with the idea it would help cover something up, but they changed plans.

And the ceiling appears to be darkened already. The normal, lighter beige color only appears at some cracks.  https://twitter.com/MichaKobs/status/990293667582799872

This is the lighter-stained side closer to the door - the far side would be darker, as well as further from the camera's light source. Looking about the opposite way, here's the best view of the smoke damage that was caused after the chlorine tank was there, but before the late-night post-attack video (Reuters photo). Note also two spots that look quite white, one with drips. Someone scrubbed the smoke off two spots. (Kobs). Maybe this was a test, before they decide washing it all off would take too long, and they may as well leave this bad sign and hope no one made much of it.

So we must have this clear order:
1) impact event / cylinder placement
2) items set and fire lit atop the rubble
3) night-of-attack video showing rubble, canister, items and the marks of the fire all in place.

Step 1 is presented as simultaneous, the same thing. But I think there's a time gap of at least days between them; they set the canister (step 1b) next to the pre-existing damage (step 1a, done by whoever and whenever), to have a fire lit beneath it (step 2).

fusible plus NOT indicated

Why the fire? This was already proposed in discussions on Twitter, and I come back to it as a pretty good guess. The black plastic plug sticking out of the valve's top is (as I gather, provisional) There is a safety valve designed to melt away in case of fire, to allow the gas to release more peacefully by a hole there rather than explode in the fire. (so far so good?) That would be "stem" in the diagram at right. ...(that would take forever to melt. It's just the screw you turn to open the outlet - plastic for some good reason, I'm sure)

Added later: new graphic shows where this safety outlet - the fusible plug - usually is: set into one side, opposite and maybe just below the outlet. It's usually made of a low-melting point metal, not plastic. There's a poured kind, and a screw-in kind at least. (Wikipedia agrees on the purpose as I described) The rest of this line of thinking applies.<end add>

I don't know these things and research time is limited, but BubSlug says on Twitter  "melting range of the fusible plug is 70 to 73C, so easily melted by the sooty fire someone lit." Some sources I saw agree on the app. temperature range, but opinions differ on whether this fire would be hot enough. I propose if it's safety they're after designing this thing, it'll melt fairly easily, and if that was the plan to melt it, they'd turn it the right way, etc, as possible. So...

As I now suggest: the fire was lit to melt the fuse. That's what let the chlorine leak out, and thus caused the frosting we see, briefly covering the smoke that's already there.

Charles Wood adds "If the fuse was melted the valve assembly would still be there and the rate of liquid release reasonably low as the fuse hole is quite small." Also, it would have a weird looking melted-away safety fuse, right above an odd, post-impact fire that might have caused that. Assad chlorine bombing, failed but aided by a fire set beneath it ... that doesn't sound as compelling as a reason to increase attacks on Syria. Better avoid sorting this all out. Get Bellingcat on that.

That would be stupid, if it's caught this easily. But if you had a chlorine tank you needed to pop open, what would you propose? The stuff isn't very deadly, unless a lot sprays right in your face and up your nose. Leaving the valve assembly visible would be even dumber. Faced with dumb and dumber options, I'd say they chose well enough.

A complication or question: I want to say "Now maybe we know why they decided to have those slats placed there, so we never did see the valve's status. They weren't for support. They were to cover up where they obviously removed that crucial part of the evidence." But as noted, the slats are already there too at the time of the night video. Did someone remove the valve already? Likely enough. It may not be actively leaking any more, and even if it is, someone with the slightest protection should be able to do that by hand in a few seconds with no problems, once the majority of the gas was released. I imagine it's the pressurized part that makes opening a full cylinder so dangerous. Or maybe the slats were there to help conduct heat to the fuse and melt it steadily, and/or to cover it up until the valve could be removed, to avoid anyone seeing it place to compare in embarrassing before-and-after images?