Why is it that you believe Powers will want to leave? He is a hard worker and has been doing the majority of the recruiting for BU...I know he is older, but he really enjoys the work and I don't see him going anywhere anytime soon. He is in his mid fifties, at his alma mater, has already been a head coach, and is likely exactly where he wants to be. I'd be willing to bet that he is at BU for another 5-7 years.
Bavis resigned on his own. ushr.com gives some details about the situation. Quinn asked Bavis to stay on. The two are good friends, just do not see eye to eye on how to run a program. Bavis was mostly upset with the university and how he was not actually considered for the job after all of his service.
I don't believe he left BU because of Quinn...I think he left because he couldn't stomach working for a university that disrespected him.