Rough Day At The Office?

I went to use the men's room on our office floor at the end of the day yesterday and found a guy in there pounding tall boy cans of Old Milwaukee. He had one on the sink and there were four empties in the trash can.

After ascertaining that he isn't a client of any of my colleagues, my guess is that he is someone who comes in off the street to "borrow" our restroom for his drinking (there have been two other occasions when I could've sworn the bathroom smelled like beer, but found no hard evidence.) Needless to say, we're going to get the lock on the door fixed.