She must have been drunk, high or distracted; talking on her Bluetooth cell phone.
She must have been drunk
People who are texting walk like zombies with their heads down.
I used to be a drunk and if I had an "exceptional" night, I would get in the wrong bedroom in my apartment or get into the wrong car.
Nineteen years sober now.
I was on temporary duty at a base in Turkey, and we had a guy in the group who actually had a real room (most of us lived in Tent-City). He was staying in the base hotel. At some point, he got drunk one night and attempted to break down the door of someone on the wrong floor (like in this case). That guy was calling the SPs, and they arrived within a minute or two. Long story short....our associate was put into Tent-City that night and lectured heavily.
Like you suggest, alcohol is probably involved.