I think it's more complicated than that. They didn't get along - evidenced by the fact he gave up almost $15M in guarantees to opt-out.

https://www.sbnation.com/nfl/2017/3/1/14599712/colin-kaepern...

There's a lot of other issues here - it's unfair to say he got "fired" because of what he did last year. He's been very bad lately - huge dropoff since he went to the SuperBowl.