Umm.... he did not break or crack his knuckle either. Those types of injuries would prevent him from just turning around and fighting Corrales right after. Basically his hand was a bit sore and he wanted to quit in his corner.
Solid fighter, probably has more skills and quickness than Clottey just not a big puncher and not as solidily built as Clottey. He's a stiff match up though because he's a good mover and boxer with skill.
Something happened to his knuckle I guess is what I am saying. Maybe he bruised it I am not sure. Either way, the injury stopped him from throwing the left hand which at that time was landing with ease and keeping margarito back off of him. Why would he just stop throwing his left if he could? to get hit more from Antonio and keep Margarito in the fight just for kicks? I just dont see the rationale to stop throwing a punch just to lose the fight and blame it on a pre-fabricated excuse. If anything, he would keep throwing the punch and try to win!