I don't know if this is related, but I was listening in my car for about 10 minutes during Coffey's show. KFRC was raising money for the boy who was shot in Oakland, so they were seriously breaking regular format - Jay was talking live without interruption for minutes at a time, taking phone calls (song requests for $ donations), and talking with Dave Sholin who was also in studio.
Just speculating, but I think Moore's show is normally voice-tracked, so perhaps there was no time to put together a VTed out-of-format show. Maybe he's down with a cold.
Was there another announcer in the evening, or did they just run jock-less?