Visible crew/equipment: In the opening scene where General Clayton is explaining the 4077 to the psychiatrist, the scene changes to the outdoor set and the camera pans to the right. As the camera pans past the hospital, a white 1970s era shuttle van can be seen driving into the set in the upper right corner of the screen. (00:01:35)
Continuity mistake: Margaret is shampooing Frank's hair; she raises her foam covered hands to allow him to kiss her. The camera angle changes and her hands are nearly foam-free. (00:03:25)
Visible crew/equipment: While in the mess tent, when Henry introduces Hildebrand to Margaret it cuts to Henry as he says that she's the best head nurse in Korea, and at the top right corner we can see the open edge of the tent set and what's behind it.
Visible crew/equipment: After we hear General Clayton in the voiceover talking about how it sometimes seems like Henry is Radar's clerk, during this scene in Henry's office we can see the shadow of moving film equipment - likely the boom, at the top, left side of the screen.
Visible crew/equipment: Right after the opening credits, in the first shot as the words "Directed by Jackie Cooper" appear onscreen, the shadow of the moving boom mic can be seen at the top, left side of the screen.
Visible crew/equipment: In the swamp, behind the General, you see a hole in the tent that disappears a second later. In that second, you see a boom mic.
Continuity mistake: The crew is getting the bad news in Henry's office when Radar reports more choppers. From behind, Henry starts to react, and when the angle changes he reacts again.
Continuity mistake: When the General comes up, Pierce and Trapper are walking away toward the camera's left. When Pierce calls for the General's attention he is shown gesturing to the open door. Problem is, that they should be looking over their left, not right, shoulders, and we should see the inside, not outside, of the door.
Continuity mistake: While talking to Hildebrandt, Henry smacks his hands together while saying "Gee, whiz!" When the angle changes, his hands are on the desk.
Audio problem: In Blake's office, he's talking to Hildebrandt about Klinger, and the camera does a close up on Blake. You hear him say "Of course", and his mouth is moving a little, but not forming the words.
Continuity mistake: Usually when you see Pierce, his hair is parted on the left side. When he is nibbling on the nurse's neck in the Swamp, his hair is parted on the right. Then the next time he's seen, it's parted on the left again.
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