I thought he made some twitter comments suggesting he wanted to go elsewhere - could be wrong but I recall it was a comment around the disparity in his eyes between salary and rookie year performance or some such.
Didn't Williams suggest that he wanted to play somewhere else after last season? Maybe his lack of impulse control was really sub-conscious calculation.
Trade him. Maximum value now before he sputters or proves his baseline. Draft 3 qbs and run Roman's 1967 Packers offensive set. Bills are not contenders.