He left sony to do this???????????
he didnt leave, he was fired because he advertised the Wii durring a Bridgestone tire commercial.
under contract he wasnt allowed to associate with other consoles since he was the face of a Sony owned character.
From what I understand, he was no longer working with Sony at that time. He had signed a contract for X period of time or X number of Sony commericals.
However you are right, he did break one of the rules of the agreement (despite the fact he was no longer making Sony ads at that time)