People tend to forget the fact that there are ways of getting someone to want to leave. Make it HR hell - crawl up someone's butt with a microscope; analyze every expense, every action, lots of early morning meetings. Mandatory reports. Every contract has language that can be interpreted creatively. Refusing to shake hands at the end of a nationally televised bowl game? Some could construe that as a code of conduct violation moving forward. Maybe you find an ex-cheerleader who "says some things". Seeds of discontent sewn in the locker room? How devious do you want to get? Make it miserable, but offer a carrot. We know your contract is worth ~40 mil. We'll smile, write you a check for 15, and tell the whole world how great you are as we part as "friends". Or.... we can keep playing this game and you can keep being miserable and at the end of it you'll be worth far less on the open market than you are today. We'll take 15 years off of your life over the course of the next five.
I know all that sounds horrible, but I'm remind of a quote from a favorite movie:
"You want a toe Dude? I can get you a toe. There are ways. You don't want to know..."
Of course, that didn't work with Stallings - they tried something similar, IIRC. It also sets a bad precedent for the next guy who comes in. So you gamble he takes the "deal" and if he doesn't, then you f-d around an found out. In the end, it's just more bad football outcomes any way you slice this poop-cake of a situation.