You ever been in a confined cage with an angry hellcat? Sometimes "advantages" have nothing to do with anything, other than the best thing he could have done was run away as fast as he could. If that was even the situation. I will say in the 37 years I've been with my wife (quite a few before we actually married), we had a couple of physical altercations where I was being an asshole and she lost her mind. I once "broke her finger". Meaning, her finger got broken by me trying to deflect several punches aimed directly at my face. At the time she was no shrinking violet as we were running a "ranch" so to speak and she could "chock" hay bales and run a chainsaw etc. Nothing to do really with Chris Beard, other than to say there are times you have to protect yourself and occasionally that means it might injure the other person. When the fists start flying at you sometimes there isn't time to consider "good" decisions.
Like I said, I'm not applying that to this case, I have no fucking idea what happened. But thinking a guy should "act big" because he "is big" is ludicrous. When someone gets out of control and starts trying to hurt you, there isn't always time to consult the "good behavior guidebook for gentlemen and college coaches".