I thought he would have far more problems and be wobbled any time he got hit clean. I recalled Canelo's KO loss of kirkland a naturally huge guy who couldnt even last 2 rounds with Canelo and was hurt far more then Khan. Surpisingly, Khan did quite well absorbing the shots.
Khan getting knocked out had nothing to do with having a bad chin. Khan was getting hit hard by the Canelo right hand to the body. I really think Khan thought Canelo was going to go there again and dropped his hands to anticipate it, but Canelo went upstair that time and Khan just was in no position to defend it. At the highest level it just takes that one split second to be unaware and lax for you to get sparked. That shot landed by Canelo knocks out most middleweights.
he didn't really land a lot to the head but i think the body shots where getting to khan after a bit...