Lowkey smart move.
His value is pretty high right now, for him at least, considering how well the Bills did this year.
He knew Orton was leaving, so that meant either EJ Manuel or a rookie at QB.
His value was almost assuredly going to tank after the Bills regressed next year, so he left with fat pockets and a solid resume to hopefully garner a HC position down the road.
He obviously didn't get the HC offer this year, but would finishing out his Buffalo contract and inevitably regressing next year have helped him in that regard?
Better to be remembered for overachieving with the Bills and Orton and quitting than going 5-11 with EJ.