I believe getting put on his back broke Junior mentally.
He said after the fight he didn't even try to work ju-jitsu he just wanted to get back up, and I believe that is what cost him the fight, the fact that Cain was able to break him.
They're destined to fight again though and Junior clearly knows his game needs work, ju-jitsu and learning how to fight and fight calmly off his back will be a big factor for him going forward, I hope so anyway. I'd hate to see him become the Heavyweight Rampage.
THE PERFECT STORM
THE PERFECT RECORD
THE PERFECT FIGHTER