His move on Button was no different to the move Shue made on Hill Adelaide 1994.
Drivers have this impulsive reaction to block when they feel iminent threat and you and I will never know the pressure these guys are under during intense racing, so lets give them a break. It was a racing incident. Yes DC did block, but JB went in very late and would probably have understeered into him anyway. If anyone had been to blame, the stewards would have taken action.
DC is very good at making his car very wide. Anyone trying to pass will become very frustrated and end up making a do or die effort to pass. This is why DC gets involved in incidents. He's guilty of being a good blocker, not a crasher.