I'd agree with that Brian, you couldn't get a new manager and deny him funds. I do disagree about o'neill though, he was certainly irritated by the milner sale and being denied the money was the last straw.
The deterioration of his relationship with Lerner certainly was a factor. He felt he was no longer being backed, sensed Lerner didn't have total faith in him. When that happens it is time to go. Pity people need to find a villain in the whole thing, when really there isn't one.