I have not heard it, but I would not be surprised. The rank Spartanness of MSU is already getting to him (witness his "look at their sideline!" insane ranting from last year). He started out 4-0 last year (against a crap nonconference schedule) and probably thought he was the shit, and then promptly dropped six of his last nine games.
It wouldn't surprise me if Dantonio mocked another Michigan athlete (read: 20 something KID). For all the good/bad Dantonio does for MSU football, he reminds me a lot of Charlie Weis- beneath it all, he's just a giant asshole. And really, nothing surprises me about the behavior of assholes.
I'm generally against classlessness on the field...but if (when) the opportunity presents itself, I hope Rich Rod runs it up on this clown. Whenever Johnelle Smith opened his mouth, hilarity ensued. Whenever this ass wipe shoots his mouth off, it's one asinine comment after another.
Dantonio burns kittens.