Seemed he was saying it wasn’t necessarily delivered by air.
That still doesn’t rule Assad out. Assad is definitely on the ground in Syria.
There are a number of players who could have delivered the agent.
Assad did it- when the “usual suspects” appear to try to cover for Putin, you know they are liars. They’ve been lying since the Nuclear Freeze movement in the 70s if not earlier in the case of BAS, on behalf of the USSR, and like Putin they dream the USSR will rise again.