Anything goes when its directed at him and very closely observed where there is an opportunity to blow the whistle against him.
Hate that a guy is allowed to drop his shoulder and initiate contact into the center of a guys chest who is in legal guarding position... not just once but multiple times in the same sequence. It necessitates falling over (encourages flopping) in order to try to get the call which judging from the non-call where Davis went down on a similar play doesn't work either.
For Jazz fans however, Karl Malone did have a very nice NBA career based on that tactic....