It has yet to be conclusively proven. Russia who has boots on the ground in Syria thinks otherwise and the UN has not concluded their investigation. Obama himself called it alleged and Kerry has been lying his arse off about the make up of the rebel forces and their having access to these chemicals. We have news accounts that show the rebels have possessed them. Turkey caught them on the border with them.
The last time we didn’t listen to Russian intel we had bombs exploded in Boston.
I agree. I have strong suspicions that other than Assad fired the gas. It is completely counter intuitive for him to do so.
That suspicion is getting a little exposure. Hopefully, more to come out on it.