I say yes there is question marks over his chin he was out on his feet for the last 3 rounds really and there were times had it been over here Khan couldve been stopped by ref Khan showed great heart to get through it. But had Maidana had the skills and energy to get another clean shot through Amir would have been ko'd Amir walked back to his corner for the last 3 rounds like he was drunk and he didn't really spring back in to life till the clapper for last 10 secs of the 12th. Amir ran to survive and Joe Cortez did him some favours putting distance between them on the breaks but as i say Amir did show great heart and the fight was very good from both but Amir still has a very dodgy chin and to be talking Mayweather is crazy and i wouldn't be thinking Alexander vs bradley winner either yet