OK, how did you come up with this?
You keep wanting this nice guy to become angry and do nasty things. Why? The PD is his friend, who used to listen to him as a kid. He's not going to tell him to piss off. When did they offer him the part time gig?
It's not the PD, but the General Manager. The OP did not say where he heard about the news. He even said he hoped it was his decision to retire(which it clearly wasn't).
The story mentioned possible voice tracking and he didn't "want to go into it". That could mean they asked him and he said no. That is speculation, but it's not unheard of. It's moot now, because he has moved on...