The worst nightmare for any MA person can be - You get into one street fight. In that fight, you only throw 1 punch. You kill your opponent. You spend the rest of your life in jail.
IMO, the best way to handle a street fight is to play 100% defense. When your opponent finds out that you have no intention to hurt him, also your opponent finds out there is no way that he can hurt you, the fight will stop, you and your opponent will live happy ever after.
One of my students told me that in one fight, he had no problem to block each and every punch that his opponent thew at him. Finally, his opponent just gave up. He told me in that whole fight, he didn't even throw 1 punch at his opponent. I do believe this can be the best street fight attitude to have.