If Petrino wouldnt have called her out in the press conference, she would still have her job. She didn't work for the university, she worked for a radio station.
Dumbass fans saw the press conference, found out what happened, and Monday morning called the radio station en masse to complain/boycott advertisers.
Yes, she probably deserved to be fired - that is just dumb, but, she would have gotten away with a slap on the wrist if he wouldn't have said anything.