The rebels want western intervention to topple Assad but its been made clear no intervention unless Assad uses chemical weapons so very conveniently somebody happens to be in an ER with a cameraman and somebody going around asking the doctors & patients all about it. The patients tell them their symptoms and sometimes it appears like they are being prompted by the doctor to remember their lines like was it a white gas and the patient says yes it was a white gas. Other than the individual who was either vomiting or just spitting out some liquid for the camera it didn't look like people there were suffering the after effects of a nerve gas. Knowing the warnings he has been given from the west on what happens if he uses chemical weapons I doubt he would hand them out to troops to just use against small numbers of people. The chemical weapons are his last stand and revenge weapon when he knows its all over and he has nothing to lose so he can have the last laugh. Assad is also moving his chemical weapons to a handful of secure sites to stop rebels getting their hands on it. What happens if the rebels kill a soldier armed with Sarin, they can then start gassing Assad's people. It would also take alot of time and planning by the people in the labs to turn lots of small arms like mortars into chemical weapons and they are issued from central stores where any soldier can get hold of them and their use is not controlled. There is no way Assad has been using Sarin, if he was using any gas at al it was probably tear gas. The chances of this home movie being the real thing are very very low.
Trump: Middle East would be more stable if Saddam, Gaddafi still in power (Reuters)
from the article: Syrian rebels claim Assad regime uses chemical weapons