I reckon the heat from the steamer softened it mate.Sorry to say but when I had the bodyshop we often saw cars come in from these sort of places with similar problems.gutting I know,but it shouldn't cost the earth to put right mate,I'd say perhaps a smart repair would get away with it but I'm not a fan of their work tbh.

If the car hasn't been painted recently you might get away with a replacement arch off another White s2?yours is still mint so could be sold as a complete kit for someone who's got a kit needing painting.