I believe there is a genuine "disconnect" between the genius who raised him from a pup and the fraud formerly known as mangenius. While they might have eventually patched up the relationship following his ill advised defection to the swamp, because Bill was well aware of the underlying ego issues that led to it, they'd been butting heads for at least a couple of years as a result of it, and it did pan out for Eric in NY exactly as Bill predicted - they turned on him despite a winning record, what transpired in spygate is the kind of betrayal few ever forgive and forget. Tannenbaum may have ultimately been the little engine who drove that train, but Eric laid the track. Tannenbaum wouldn't have even gotten the GM nod in NY had he not landed Woody a Judas willing to spill the beans to land his first HCing job prematurely. I'm sure Eric would say with all sincerity in hindsight he never intended for what he did to prove so costly and damaging to his mentor, but the trouble is you can't take stuff like that back after the fact. You have to live with the consequences, just as the man who gave him his shot and this organization that launched his career did.
The example of the two Bill's isn't a remotely relative analogy. They eventually reconciled largely because the one who behaved badly throughout his career woke up one morning and realized he had no friends from among the myriad of careers he helped launch because despite the significant role they played in his success he chose in the course of each of their relationships to universally treat them like ****. Little Bill is not in remotely the same situation. Guys like Josh and Scott and Tom Dimetroff and Charlie and RAC and ... and a host of college coaches like Saban and Hill and Ferenz and Meyer can all attest to the fact that he treats his collegues and peers honestly and fairly in the process of often teaching them everything they come to know. That's exactly what he did for Eric, and in return he got an ego driven knife in the back that while he managed to survive scarred him for life.
Bill will generally forgive a player who in the heat of battle with his career on the line emotionally lashes out at him. What Eric did was on a whole other level. It was akin to Tom Jackson squared. That kind of unwarranted attack he never forgives or forgets let alone when it emanates from someone he treated like a son. Not to mention when the apology is launched via the media in a pretty transparent attempt to salvage his downward spiraling career. They obviously haven't spoken or had a functional, civil relationship in five years now. If I were Eric I wouldn't hold my breath for the day they do. Loyalty and trust are huge with Belichick, and Eric has proven incapable of either. Just ask his handpicked Cleveland GM George Kokinis, formerly and presently of the Ravens.