IMO, he was already starting to slow down by the time he got rocked. I've actually questioned JDS's cardio for a while now. It's good enough to coast to a decision if he doesn't get the finish in the 1st, but it's not nearly good enough to keep up Cain's pace for 3 rounds let alone 5.
Well I don't think anyone in the HW division is up to that task with Cain.... but my thought is if JDS can figure out one of the other two items. He might force another early stoppage.