I can't help but think there was a little "big brother/little brother" dynamic here that hurt Ainge.
Larry is so competitive, and you know he probably felt he had a mental edge on Danny as the star/mentor from back in their playing days. I bet he tried to exploit that, and Danny was patient enough to back out.
Usually we think the "Boston connection" facilitates deals, but it could have gone the other way in this case.
Can't blame either one of them either. They're both good GMs. Most deals happen between good GMs and bad GMs.