Body on body contact, as well as lots of other contact in the game, is not a foul because no advantage is created.  Contact that creates an advantage is callable as a foul.  Doesn't mean refs will call every one of them - sometimes they set the bar pretty high.
Having said that, anyone who construes that play as anything other than a foul on the MD player needs to have their head examined.  It was without question the worst non-call I can remember seeing.  And yes I have ref'd (at the high school level not college, but still).