You decided to take clothers and hide. So you take his suit, pipboy and weapon and hide in cupboard. It's not so easy with such a stomach, but you manage. Leaving a small gap, you are hiding.
Soon you see how the guard comes out of the barracks, he sees that the room is empty and returns, saying to someone:
"It's not here, I'll check it in 15-20 minutes."
When he leave the room you quickly dress up, his pipboy was with a biometric seal, so for you it is useless.
You can come back to cameras, or go away.