I've seen/heard of this phenomenon in the past.  My friend works at a university that got embroiled in controversies and cronyism and nastyness, etc.  What happens is faculty begin looking for jobs elsewhere, and the prime season for getting job offers is late January through late April (we are in the season now).  Well, at USM and other places faculty receive their contracts for each school year in late June or early July, and they are usually due on the President's desk by late July.  When things get nasty, some faculty who have accepted job offers back in the Spring tell very few people, if any.  They never inform the univ they are leaving, they just fail to sign and return their new contracts.  Because Summer is a time when few people traverse campus, the president's office thinks not getting a few contracts is part of the normal course of summer.  Sure, the send out an e-mail reminder or place a quick call to the departmental secretary.  But, no one has seen Professor Doe and they simply guess he is out of town or something.  Meanwhile, none of them know professor Doe has taken a job somewhere else and has cleaned out his office over the course of several late-night sessions when no one's watching.  What happens, the school finds out on the first day of classes that Doe is gone forever.

Some retirees get so mad that they teach the first 3 weeks or so of Fall semester, then they turn in a 2 weeks notice and retire at mid-semester.  I know places where this became somewhat commonplace after things got soooo bad there.

I'm not advocating this.  I'm just saying that the further USM sinks into the abyss the more common the uncommon will become.