He may have underestimated Cain and looked like he was holding his previous 64 second victory over him too much to his heart. Even in the pre-fight press conference, he said "This is not a rematch for me, this is a rematch for Cain". That might've fucked him up big time. You don't take Mr. Velasquez lightly, because if you do you get fucked. Cain did what he had to do and kept on the pressure, which may have surprised Junior. JDS will be rebounding like a beast though. Can't wait to see him next
Still, when Velasquez/JDS III comes around, I'll be picking Cain again.