I wonder if anyone's checked the minibar in the room for ammonia leaks? It's very rare, but sometimes the gas canister in a mini-fridge can develop a leak, which if unchecked can leak into the room and be potentially fatal. I heard about a woman who was throwing up all night in hotel room, not realising that the pungent smell in the room came from the mini-fridge.

If that were the case, the smell would have been detected as soon as anyone walked into the room; who knows? Maybe it's part of the investigation, but that's just me reaching because I really don't want Cory to have relapsed.