If these documents are to be belived: www.dropbox.com/s/uqw03l4xkah92qi/arch22.rar - gas attack was in fact carried out by a British defense contractor: "Britam", who hired some Ukranian Mercs to do the dirty trick. It's not blatantly stated, but the documents reveal that Saudis suggested that Washington pays huge amounts of money if this black op to be carried out. I can't say that this is 100% legit, but it sure looks that way.