Why is everybody assuming that the decisions weren't made months ago? I think it was fairly obvious to everyone involved that Trev had a quick hook ready to go on Frost, and he would have informed all coaches coming here that it was a possibility. If you think Mickey didn't know what could have happened months ago and not had a plan (and worked with Trev to do so), then you're sorely mistaken.
Besides - I believe that it was in MJ's contract that he could retain his pay no matter who was named the head coach here, right?