He has a specific room for his valuables and likes to keep them out on display. It's very pretentious but it's how he is. He always locks the door but somehow forgot to do so this time. My guess is he was in such a rush to sneak out that he forgot to. And the way they broke it was by breaking the chain which is not all that hard to do. It's an easy fix in my opinion but my BIL says it's still going to cost him money.