Howard's an emotional child who instead of remembering things and taking revenge on the court at a later point, has to get his words in immediately. The Wisconsin coach was dumb enough to take the bait.
Shouldn't have grabbed him, but Howard was clearly ready to go as soon as Gard stopped. Then he just couldn't let it go once they were separated. He should be thankful he hasn't been fired and needs to get some therapy. Not as many people know he's already had issues, and they aren't going to come to his defense after he does this the 3rd and 4th time.