Backed in to a car that was parked in a no parking area.?

Well, I didn't drive to work today so when my dad picked me up he wanted to stop off at Walgreen's on the way home. When he has backing up to leave he backed into a parked car. The thing is it was a fire lane no parking area. My dad has talked to his insurance company about it and they said he was at fault because it is a "moving violation". Now, is there anything else we can do? We aren't looking to sue anyone or anything like that, but would a lawyer be able to fight it and make it to where she is at fault for being parked in a no parking area? Any information helps. Thanks everyone!