Parking Brake '02' Cabrio

Just heard from my daughter's mechanic that in order to repair the parking brake, he has to replace both rear calipers!!!!! The brakes are fine, there is just nothing on the parking brake when you set it. Say it isn't so!!! She is in Denver I'm in Seattle so can't look at it.... Is he taking advantage of the situation or is that accurate? If so, what idiot would design a parking brake system that should it fail both calipers need to be replaced?:banghead: