Hmm, well I also listened to the 4 min. clip of that...,
I don't really think that the show's hosts did anything wrong, they were genuinely taken of guard by the admission and were quick to end it and offer any help they could for the girl as far as free counseling etc. If anything I think the mother shouldn't have put her daughter in that position. She knew of the situation that her daughter had been through, she didn't disclose that to the show's hosts and set her daughter in a position that forced that to come out.
There's plenty of show's out there that employ the use of lie detectors in order to be more edgy, to try and get a guilty admission from people in the aim of entertainment, that in itself is kind of crappy, but no one is forcing these people to take part. I don't think the aim of this radio show's hosts was to be exploitative of what this girl had gone through, they just thought it might uncover some school wrong doings, a little bit of teen age scandal that would be things that we've all been guilty of.
In my opinion they shouldn't be penalized for something that was pretty much a surprise situation that could have been avoided if only the mother had disclosed the information before hand.