It could be as simple as this: Dave was not shy in acknowledging that he would've liked to move to Knoxville when we were looking for an AD. UTC leadership undoubtedly took note. Having a guy on board in a key position who you now know for a fact would rather be somewhere else can get under the skin of some. Friction develops. Given a few months, it grows into something that can no longer be ignored. Conversations take place. Folks finally agree things can't go on this way. One agrees to step down, the rest accept. It's mostly all civil, polite, restrained. No screaming or recriminations, just a parting of the ways.
Nothing really shocking in all that, just human nature playing out over time.
Good chance that's all this is.