I find it funny how someone reads stats or figures weight class are the only things that determine stoppages. No matter what the numbers are, the regardless of weight or history of the opponents... The punches that can get you are the ones you never see coming. Perfect example, being feather fisted Corely having Cotto dancing on queer street before.
Margarito was a murderous puncher (with or without plaster), but his punches could be seen coming a mile away. Mosely stood in front of Cotto and tried to slug with him a good part of the time instead of using his foot work and angles and timing. Judah used angles and speed and rocked Cotto too, then Cotto went to the cup twice.
The fact remains that Cotto is wide open for the uppercut all day, every day and he has a bad habit of dropping his hands before he shoots his punches and is bad at defending consecutive body head punches with the same hand. On top of that you have an experienced trainer looking to exploit it all. The window of opportunity is definitely there, whether people want to believe it or not.