He doesn't need to explain himself, Union needs to explain their actions. Even great coaches have been let go for hitting players in the past and throwing punches at an opposing coach and actually hitting an opposing player is not acceptable in college sports.
And yet, he is still coaching at Union. Why???
I congratulate the Union team for their accomplishment, and they evidently have a great coach who led them to the top. But does that give him the right to physically attack the opposition??? I think not.