I doubt it had anything to do with rex. TT was running out of bounds on a meaningless drive to end the game and the LB pushed him out. He took offense, even though it was legal, since the only result you're going to get is an injured Tyrod. When he started shouting, Reshad Jones got in his face to kind of... rub it in I guess?
They then did the same thing, actually late the 2nd time, and got flagged for it. I get wanting to hit people, but when he's a step from out of bounds and you're up 11 with 1 minute left, what's the point other than intent to injure?