Something that just crossed my mind is whether this method is destructive or not. Is it possible to steal the key, read it, then give it back to the owner?
Their method was destructive to the outer casing, because it was easier. If you wanted to clone a key it is likely you could find a way to either avoid destroying the outer packaging or replace it with an apparently identical case, at some expense. They don't necessarily need to damage the actual chip (although they did trash at least one during R&D)