Seems like a very harsh decision looking at it from a distance.
The job Bunney has done appears to have been an excellent one. Taking the team up in to a higher division and finishing 4th should not be scoffed at, and certainly suggests an ability to coach a team. It will be interesting to see if the senior players can improve on their 4th place next year with a manager who they perceive can coach them.
Above all else, it sounds like it’s been a messy split, which is a shame, it sounds like Bunney did a lot more at the club beyond his remit than just manage the team. Their loss will be another club’s gain.