You are on point. He left because he had an out clause in his contract regarding ownership changing. It did. He opted out. I remember many of the talking heads and NFL types getting miffed about him doing it when he had clearly turned the Bills around. They tried to make him out to be a quitter. He knew what would happen with the change was opposed to the direction the org needed to go. I see him following through and actually quitting a big deal in favor of his character. He is committed to what he believes and means what he says.
Fast forward to today. He went to work for the Jags, steps in successfully as the interim and possibly heading to the playoffs in his first full season. If he sees things wrong with the Jags that will not be addressed by ownership, he will leave. That makes him viable for UT. He wins and he does it his way. If you agree to his terms and don't mess with it - you win. He's got plenty of CFB experience and has recruited a lot. UT would have to hire the guys he says. Sounds sort of like the approach of certain coach in Alabama that is the current GOAT.