Continuity mistake: After Frank picks up the still, his hands alternate from left hand above right to right hand above left between angles.
Continuity mistake: This episode has the heater in Henry's office in front of the window, and the wall by the window blank. Later the stove is by the window, with the diploma by the stovepipe.
Answer: Even an Army field hospital would have SOME weapons for self-defense if the enemy attacked. What's meant is that it's not a combat outfit, and therefore wouldn't have enough weapons to actually attack anyone. (It's also mentioned a few times that the Officer of the Watch is supposed to carry a pistol at all times, but Hawkeye refuses to do it when he's in charge and Colonels Blake and Potter don't enforce the rule).
Captain Defenestrator