McGinnest committed a crime on video. He casually walked up and beat a guy. It won't matter what happened before that as far as the law is concerned. He can't claim self defense so...what will he tell the judge? What don't we know that would lead the judge to say "oh, that makes sense. you may go free"?
You must be thinking of some defense that would free him. Why don't you just tell us what it is---and spare us your "rapists, sexual absuers, child abusers, domestic abusers" stuff. Ol' Willie isn't some Street Avenger hunting down bad men. Even if your bizarro scenario was true--it's not a legal defense, obviously.
So tell us what he tell "the judge" that gets him off and back into "society"?