Anae wanted to resign in the middle of the 2010 season based on major disagreements between him and Reynolds. BYU asked him to stay until the end of the season, which he did. There is no way that Anae would stay with Reynolds still on staff. Bronco purportedly wanted to keep Anae, but wouldn't get rid of Reynolds. Anae found a new job at Arizona.
What's left out of the story? Did Bronco try hard to keep Anae? Nobody knows, but it's apparent that Reynolds was staying and that Anae was asked to reapply. It was well known that Anae wanted to resign for a couple months, so there was no effort to appease Anae with his demands.
The only conclusion I can draw is that Bronco didn't even give cursory effort to get Anae to stay, so it was a de facto firing.