Did the chemical attack in Douma really happen?

Amid the war of words between the West and the Rest and the cacophony of tinkerweb trolls (and "Russobots"?) claiming Douma was a (probably US instigated and sanctioned) 'false flag', Robert Fisk offers a third way:

It was a short walk to Dr Rahaibani. From the door of his subterranean clinic – “Point 200”, it is called, in the weird geology of this partly-underground city – is a corridor leading downhill where he showed me his lowly hospital and the few beds where a small girl was crying as nurses treated a cut above her eye.

“I was with my family in the basement of my home three hundred metres from here on the night but all the doctors know what happened. There was a lot of shelling [by government forces] and aircraft were always over Douma at night – but on this night, there was wind and huge dust clouds began to come into the basements and cellars where people lived. People began to arrive here suffering from hypoxia, oxygen loss. Then someone at the door, a “White Helmet”, shouted “Gas!”, and a panic began. People started throwing water over each other. Yes, the video was filmed here, it is genuine, but what you see are people suffering from hypoxia – not gas poisoning.”

There were food stalls open and a patrol of Russian military policemen – a now optional extra for every Syrian ceasefire – and no-one had even bothered to storm into the forbidding Islamist prison near Martyr’s Square where victims were supposedly beheaded in the basements. The town’s complement of Syrian interior ministry civilian police – who eerily wear military clothes – are watched over by the Russians who may or may not be watched by the civilians. Again, my earnest questions about gas were met with what seemed genuine perplexity.

How could it be that Douma refugees who had reached camps in Turkey were already describing a gas attack which no-one in Douma today seemed to recall? It did occur to me, once I was walking for more than a mile through these wretched prisoner-groined tunnels, that the citizens of Douma lived so isolated from each other for so long that “news” in our sense of the word simply had no meaning to them. Syria doesn’t cut it as Jeffersonian democracy – as I cynically like to tell my Arab colleagues – and it is indeed a ruthless dictatorship, but that couldn’t cow these people, happy to see foreigners among them, from reacting with a few words of truth. So what were they telling me?

They talked about the Islamists under whom they had lived. They talked about how the armed groups had stolen civilian homes to avoid the Syrian government and Russian bombing. The Jaish el-Islam had burned their offices before they left, but the massive buildings inside the security zones they created had almost all been sandwiched to the ground by air strikes. A Syrian colonel I came across behind one of these buildings asked if I wanted to see how deep the tunnels were. I stopped after well over a mile when he cryptically observed that “this tunnel might reach as far as Britain”. Ah yes, Ms May, I remembered, whose air strikes had been so intimately connected to this place of tunnels and dust. And gas?

Fisk it here!