Continuity mistake: When the chopper carrying the soldier with the wounded back takes off, the sky is cloudy and, even accounting for the poor quality of the film, the weather looks very dull. The shot changes to show Radar, Hawkeye and Margaret watching the chopper leave and it is now bright sunshine. (00:44:20)
Continuity mistake: After Radar calls assembly, Potter starts to address the personnel. Accounting for Hawkeye, BJ, and Margaret in Surgery, there are only thirty-three people there. In the episode "Dear Ma" (S4: Ep 17), Radar wrote that there were almost two hundred people there.
Continuity mistake: After a distant aerial shot of Potter's chopper, the camera closes in for a close up. When in the distance, the rotors are running full speed. In the close up, they are barely running, just enough to make the familiar whooshing sound. The chopper that they are in is being raised and lowered to simulate flight. Also, if you look in the canopy in front of Potter, you can see the camera and crew's reflection. Then when the chopper is over the building, the sound of the blades is still the slow moving whooshing mentioned earlier, instead of the full power sound it should be.
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