Just leaving Mr Wenger out of this at the moment, I think most people would agree that Costa was disgusting in that game and deserved to be sent off on the day. Quite possibly Mr Wenger's quite justified complaining (not whingeing) had no effect on the final outcome
But he often seems to be in the right, and it is Mourinho who seems to have entered the realms of fantasyland in defending his team and his record this year.