I can say this much. His decision to retire surprised TStan.
TStan was getting some pressure from a few of the bigger donors, but not enough to move on from CPJ just yet.
Insofar as it matters, this is in line with my understanding. I've heard some of both 'sides' from people that were 'in the know'. Like so many things, the truth is in the middle and point of view matters a lot. When TStan came in CPJ had an engaged boss again for the first time in years. Under Sasquatch, CPJ got to do everything exactly how he wanted - for better or worse. TStan wanted to try to give CPJ the resources he said he needed to win bigger. But he was also asking CPJ to do things he hadn't wanted to do:
play the recruiting
game, butt-kiss the media, 'branding', make staff changes, maybe even 'modernize' the offense. CPJ thought a lot of that off-field 'Dabo' stuff was pretty silly. TStan didn't like the 3O being our perceived identity. He wanted the program to be bigger than our offensive scheme.
CPJ could have stayed effectively as long as he wanted. (Unless he started losing really badly.) But he'd have needed to do things he didn't want to do. 2014 proved to him that he could win 'his way'. But from the outside perspective, CFB was moving on and changing. By the end, he wasn't having fun anymore and didn't want to put in the effort to retool the program the way TStan wanted. He was an old dog who didn't want to have to learn new tricks. He'd won a lot his way, he decided he'd rather go play golf.
Leaving when he did was his choice. To some degree, he made that choice because of 'pressure'. But the pressure wasn't for him to leave, the pressure was to make the changes his boss thought needed to be made to win. And, most importantly, to win.
Honestly, IMHO, if we had half of CGC's hype, branding, and recruiting and half of CPJ's coaching acumen; we'd be winning like 08-09 right now.