Which former co-worker gave Phil Ceppaglia the nickname 'Showkiller' and why?

KORNHEISER, the Washington Post columnist and host of “Pardon the Interruption,” came up with the nickname. Ceppaglia was screening phone calls on that show one day, and he typed the wrong hometown of a caller. When the caller corrected Kornheiser about his home, the host stopped the show — and started lambasting Ceppaglia (who had only been at ESPN a month).
“Phil’s a dope.” Kornheiser said.
“Phil’s killing the show,” his co-host chimed in.
“Phil’s a showkiller,” Kornheiser replied.
It’s stuck.
“I have friends who call me that — my name’s no longer Phil, it’s Showkiller,” Ceppaglia said. “It’s different ... very different. It would be a lot different, I imagine, if people knew what I looked like. There’s a good deal of anonymity in being just a voice. Nobody recognizes a voices unless your name’s James Earl Jones.”

He also hung up on President Clinton when he was about to give an interview on the show.

Yay and wow to both of you. I was sure this one would be more difficult, but once again I have underestimated the brain power of the FT peeps.
As for not knowing what Phil looks like, every picture of him posted to the ESPN website has either a black box or a picture of Mike Bibby superimposed on his face. Rumor has it Phil's in the WPP.