I work as a leader in a professional setting. If I was in a disagreement with another employee, touched their elbow to try to explain my perspective, and what that resulted in was them pointing their finger in my face, scrunching my shirt in their fist, and striking one of my team... I wouldn't be disciplined. They would be fired, barred from the premises, and explaining themselves to authority.
(If for no other reason than to the organization itself protecting itself from lawsuits)
In a professional setting, there is the expectation that you should be able to non-violently touch/interact another person without violence erupting. Period.
If UM and the Big 10 want to go ahead and tell the world that the leaders of their men aren't expected to be safe and professional, that's their prerogative. If they refuse to fire Howard, that's what they are doing. If they discipline Gard for touching another coach, they are saying that one should expect violence for touching an elbow and speaking to someone (which is admitting that you do not have the expectation of professionalism).