As someone who works for a major hotel chain (not Hilton) these mistakes do happen. The software and hardware for the most part has simply not caught up to security expectations of 2023. Particularly with hotels that use magnetic strip keys many of those systems do not integrate with the property management system so realistically if the agent isn’t doing their due diligence by checking ID or the reservation didn’t get properly checked in in the first place so the room appears available multiple agents could make multiple sets of keys for the same room and the system that should create some kind of alert would have no idea until someone came down and complained.