What most people have lost in what Jimbo did, his actions were not actions out of anger. If they were, then he would deserve a lecturing about anger issues.
What Jimbo actually did was try to keep his team out of a fight, penalties, ejections, and suspensions. He first tried yelling at his players, but when he saw that was not getting the attention of Dobson, he had to resort to breaking the kids focus on the opposing player who was being provacative by breaking his focus. If you review the play/moment, he didn't jerk the face mask up and down/side to side in a way that would hurt Dodson. Yes, he grabbed his face mask, but it wasn't a violent, angry shaking. It was more of a "look at my face" and read my lips, cut this crap out or you're gone from the game.
Just my interpretation.