Why would Trev have been fired? He had just hired a football coach that most of the country thought was a good hire, he put on a volleyball game that was the largest woman's sporting event in the history of the earth, donations were fine. He certainly made a few mistakes in his short time but that can't possibly warrant a firing faster than Moos or Eichorst who were terrible. And if he was so terrible why would a huge AD hire him. He just left for greener pastures, more money, more promotion opportunity, more clout, more power and because he probably knew that Rhule was terrible and couldn't take back the hire. He was tied to Matt Rhule, and the only smart decision was to get out before the bomb went off.