How drunk was she?
I don't recall all the facts of the case, but I've tried to use my hotel keycard in the wrong room on a couple of occasions and can tell you that when you're convinced that you're in front of your own room, you first thought isn't 'gee, maybe I'm in the wrong place.' It's more like, 'why isn't my key working?'
So I can see how her explanation is entirely plausible, especially considering the recorded 911 call.
She had just left an extended shift at her police job ...something like hours.