Yeah, she never heard of it happening before...bullshit. It happens all the time. It's happened several times to me, and I don't even stay in hotels that often. One time people came in our room in the middle of the night, having just booked the room we were already in.

Maybe in your case they just hadn't made up the room yet. Usually, it's probably human error.

I suppose there was at least one advantage to the old days when there were physical keys.