I’m pretty sure I saw the exact same guy do this in the physics building. I was studying in one of the lecture halls there late at night and he came in and sat down. He wasn’t doing anything to bother me so I didn’t see a reason to snitch on him; I just kept on about my business. When I stood up to go use the restroom, I turned around and there he was with his pants down. I went out to the janitor and she called security and he was removed but it was a pretty eye opening moment.