Did everyone forget that the Russians and Syrians didn't deny that Sarin was used? They just said it was that the planes destroyed a Sarin factory, and that it wasn't spread from the airplanes?
So to argue that "oh, the entire attack was fake and never happened at all" is just an invention of the internet. All the parties actually agreed that Sarin was there, and that it killed people.
Maybe you know. Why do people get so het up over the use of chemical weapons in Syria?