I honestly don't recall the punch Margarito landed on Cotto while he was down, but in the case of Abraham against Dirrell it was just so clearly meditated upon, Dirrell was on his knee for a good second or two, you could see Abraham deliberate throwing a punch, hesitate further, and then decide to indeed clock him with the other hand. It had to be a DQ, I can't believe there is so much debate about it.