I got locked in a bathroom once. The lock was just faulty and wouldn't open after I locked the door. The house was full of people, so I just called out. If he was home alone, might have panicked and thought no one was coming, or tried to spare the embarrassment of calling someone out from the street to help him.
Poor guy, I hope he's gonna be alright.
Strip the doorknobs to keep the lock from unlatching. A credit card will pop the latch bolt. Be sure to permanently lock the bathroom window to prevent an escape. We removed the windows in each bathroom. Panic
You son of a biscuit eating bulldog!