I think he was getting roughed around by Vandy players who were there and not so happy about the (barely inbounds) hit. He was clearly looking the other way and probably though tit was just part of the tug of war going on.
That said, I dont think JJ shed many tears about it, in fact looked kinda stoked when it seems he found out. Someone else was saying that JJ was saying yeah, I stepped on his head! but I dont know that for sure = and even so, I am not sure he knew that he was stepping on him without a helmet, etc because it was kind of a scrum.
Either way, definitely did not seem like an intentional stomp on a guy;s face. No doubt ESPN will run it that way though in the weeks leading to our bowl game. Here is a pre-preemptive F THEM to ESPN!