The Belgian journalist reporting, is on the record for supporting the FSA.
Personally I hold to the theory that one or a few of Assad’s generals went rogue and took matter into their own hands. If that holds to be true, then there is internal power struggles within the regime. That said, it most certainly is true that FSA linked groups have been using chemical weapons in the past, I remember a video from about a year ago which showed them using agents in a test on small animals in a sealed aquarium, rabbits I believe. But before we say it’s one way or the other, lets wait until more conclusive evidence is forthcoming. Here’s more grist for the mill.
H/T: Vlad Tepes & Doris Wise Montrose