"Personal slight" at work is not personal.

I don't know if Adams was let go over a personal slight. It is not definitive AFAIK, why he was not renewed. 

I do know most of us would not be retained if we slighted our boss or boss's boss, aka the GM.  It's not personal when it's a disagreement with your boss. It's professional so I have a beef with Kelly Dewer's comment:

Whatever happened behind the scenes between Adams and the Chicago front office had to be so severe that the team was willing to cut loose one of this league’s great basketball minds in order to avenge a personal slight. Of course, this can’t possibly be enough – because no amount of behind the scenes carping and complaining should be enough for a team to let Ron Adams walk.

No amount of carping by an assistant coach is going to sway a front office so why bother?  It just undermines authority to "go after" your boss's decisions.

If Adams was speaking candidly about the roster or front office decisions, that second guessing the organization would have been enough to warrant not bringing him back. Adams was not fired, he was not renewed.