Boy, oh boy. I'm really starting to believe that the FIA is Ferrari biased after this ruling. And I always said it's a conspiracy theory.
As for the incident itself: I could agree that in general, a move like Lewises at La Source is debatable, if the advantage gained by cutting the track had not really been given back. However, in this case, a steward would have to take into account what went on before the advantage was gained and the position of the cars relative to eachother.
Lewis had considerable overlap before he cut the chicane (which was unavoidable). He slowed down after cutting to a point where he was fully behind Kimi. So, any advantage gained was given back, maybe even more. Therefore the FIA decision is plain wrong, imo.
It was a damn exciting race, though.
Btw: The GP2 races were even more exciting. There was more overtaking going on than in the last 5 years of F1 combined. (albeit at least one questionable decision by the stewards regarding the unsafe release of Senna).