Of course the guy had mental issues. That’s pretty well established. However, there were no issues that I am aware of in the last three years or so he spent with the Bills. Something triggered him, the contract issue being the most likely candidate based on publically available info. It correlates with his behavioral change.
It’s all speculation at this point since we don’t know what else may have changed.
They throw away $3.5M on Coleman, but cut Richie’s salary, by what $1M/yr when he is playing at a Pro Bowl level and they are weak at OL? Stupid. They surely didn’t know he was going to go off the rails, but at the very least, did they think he would be happy? The contract offer was just plain dumb.