UN investigator Carla Del Ponte said that there is strong evidence that the rebels used chemical weapons, but that there is not evidence that the government used such weapons:
This is not surprising. Haaretz reported on March 24th, “Jihadists, not Assad, apparently behind reported chemical attack in Syria“.
Unfortunately, history is repeating.
The American government attempted to blame Iran for the chemical weapons attack on Iraq’s Kurds.
And see this.
Too serious for you? Here's a little comedy (don't worry, this couldn't possibly be real ... it obviously has to be satire ... right?):