I have too. In his position, I would not have used it for bringing supplies up to the room, but it could easily have been my primary escape route. Even if it looks clear, the public elevators and stairwells are almost certain to be monitored, while the freight elevator has a (small) chance to be overlooked. Or perhaps a service elevator to the second floor (if that is public areas rather than rooms), and then an open staircase instead of an emergency staircase that goes to the top for descending that last floor.
I think if you park in the self park garage over three days you can bring a lot to your room with carts. If there are three or two shifts monitoring cameras you bring the bags up at different hours.