Welcome to the Hotel California...
I was at a doctors office about 3 years ago and after the exam I got dressed (was in the paper outfit...). I came out of the exam room and notice there was no one there. I went out in the hallway and to the elevator and left. If I was locked in I suspect I would have manage to get the lock open and I am not a Marine.
He should be happy he managed to get inside a clinic!