I'm sure there were a lot of different emotions and motivations at work in Doc's head and heart on this matter. Doc seemed to have way more problems with the team this past season than since before KG arrived and I'm sure that part of him wondered if it wasn't just time to move on. On the other hand, I'm sure Doc also felt some pull to come back and help KG and Paul ride into the sunset. I mean, KG wouldn't okay any trade as long as Doc was still around and that probably meant Paul would have stayed with the team for at least the coming season as well.
But the bottom line is that when the Clippers expressed interest, Doc decided that he didn't want to deal with a rebuilding effort when he had that kind of an alternative. That might be forgivable, but I can't stomach Doc trying to pretend that Ainge is the one who pushed him out when he was perfectly happy to stay.
Mike