Some people are really twisting themselves into knots defending Howard. Gard didn't "grab" him; he placed his hand on his arm. Coaches do this all the time in the handshake line, and in fact these two have been pretty buddy-buddy previously. It was hardly a physical gesture.
Furthermore, Howard grabbed GARD by the lapel shortly afterwards. Finally, Howard was so shaken and threatened by the hand on the arm that it took him almost 15 seconds before he threw the blow. Oh wait! I should point out that he didn't hit Gard, he hit another guy! To paraphrase Stephen Stills: "when you can't hit the one you want, hit the one you're with."
As an aside, he was upset about the timeout? Gee, don't slap on a press at the end of a game you have lost. I recall SU football being up big on somebody late in the 4th Q and the opposing team started blitzing. Coach Mac promptly threw deep for a TD. After the game he said "that was my way of saying "you want to blitz? Let's have some fun" "