The punch that Green landed didn't need to be hard because of WHERE it landed. It landed right on the temple. What that does is it short-circuits your control of your legs. There's nothing really wrong with your head, but your legs just won't work! Think of the first left hook Mike Tyson landed on Lou Savarese or the shot that Kostya Tszyu KO'd Zab Judah with. I'm not sure the fight would've gone differently, but Jones had his wits about him.