Who has been using chemical weapons in Syria

The use of chemical weapons in Syria is being pinned on the Assad regime, I'm not sure why as the BBC themselves aired this interview with Carla Del Ponte in May.

A leading United Nations investigator says she is 'stupefied' by the testimony from victims of the Syrian conflict that rebels have used nerve agent sarin.

Carla Del Ponte told Swiss TV there were "strong, concrete suspicions but not yet incontrovertible proof".

She said her panel had not yet seen evidence of government forces using chemical weapons.

So why were Barack Obama and other Western 'leaders' not interested in the accusations of rebel use of chemical weapons in May but are very excited by the rumoured use by the Assad regime? Is it possible that Barack Hussein Obama and his dhimmi friends want to protect Al Quaeda from harm?