So, the thing about the Cena bump is that he could very easily still have a broken neck.
There are tons of shoot interviews from indie dudes that talk about how the heard a pop in their neck and kept wrestling and found out later that night that they couldn't walk and they had broken their neck. I swear there was one from some WWE guy that went backstage and kept asking someone to help him crack his neck because it felt out of place, but no one would do it and the trainer came over and did some tests and, yep, broken neck.
This is such a godawful business. :/