I was the engineer responsible for locking systems on all Vauxhall/Opel models for a time so through my connections with supplier I learnt a lot about how easy it is to pick practically any lock, so nothing surprises me. Over the years I have been called several times to help friends who have locked themselves out of their cars or homes and it has usually been possible to open the locks without damaging anything. In cases where damage did occur, this was only because I didn't have the right tools at hand. Given the right tools, and one can assume that the 'professionals' have these sort of things, any lock can be picked without any visible damage. Cutting or grinding a lock open, for example, is something that only the amateurs do.