It's already kind of irrelevant though - the US and it's allies have already got their heart set on regime change whether or not Assad's used chemical weapons against his own civilians. A lot of this is just arguing over the casus belli and it shouldn't distract us from the bigger picture.
My gut feeling was also that it didn't make sense for it to be Assad, the timing of it just as UN weapons inspectors were present, the fact the Syrian govt seemingly had the momentum without using those weapons that could trigger western intervention, and since then the reticence of the US to publicly share this cast-iron evidence they speak of at the UN. All that together's enough to put doubts in anyone's mind. But I've seen stuff since that's put a few of those initial ideas to bed. For example I couldn't understand why govt would attack an area so close to the capital, so close to their own civilian supporters, whilst there's UN people knocking around. But then I saw that report in le figaro suggesting there might've been US undercover special forces in Ghouta, and then I remembered how the Syrian's had said they'd not use chemical weapons except unless there was "outside interference". Perhaps the use of chemical weapons was to send a message to the US and Israel? That the gloves come off if they start getting any more involved?
Then I read another thing saying how even though the govt has managed to win some key battles elsewhere in Syria they've had little success in shifting the rebels that were camped out to the east of Damascus. Then I found out how strategically important it was, the eastern flank of Damascus of Irbin and Ghouta, because that bit is just a few miles directly north of the main arterial road linking the centre of Damascus to Damascus International Airport, one of the regime's most important lifelines. Clearing them out must've been a pressing concern for Assad, and the government's lack of success at doing so must have hugely been hugely frustrating. So I've had to rethink some of my initial assumptions and misgivings about what's gone on, because it first I thought it was an irrational act of madness for Assad to do that, but I don't think that any more.
I don't buy the stuff about it being some rogue commander that the zero hedge article insinuates, if the chemical weapons unit of the Syrian army has lost discipline and starting using chemical weapons then it's over for Assad, that's the sign of all discipline breaking down and the end being nigh. We haven't heard anything to suggest that was the case before August 21st.
Then on the other hand there's some big problems with idea that some rebel group did this. One of the longstanding problems the rebels have had, and one of the reasons they've been losing recently, is that the don't have much by way of heavy weapons and they're not very good at using them. Then all of a sudden they launch a co-ordinated chemical weapons attack with artillery, precisely on specific rebel-held civilian areas, in some "false flag" operation to frame the Syrian govt. Since when did the rebels go all delta force? I'm not sure they've got the ability to actually pull of some of the more fantastical scenarios people are putting out there. It's not impossible they did, I can see what they'd stand to gain by doing so and I wouldn't put it past them ethically, and so i'm trying to keep an open mind, but at the same time some idiots are just going full infowars and coming out with ill-founded conspiracist stuff.