Good-Bye Radar: Part 2 - S8-E5
Visible crew/equipment: After Radar tells Colonel Potter that he decided to go home after all it cuts to Hawkeye walking into the office, and just as Hawkeye opens the door we can see the top of the set.
Good-Bye Radar: Part 2 - S8-E5
Other mistake: When Potter enters the Swamp, his rank insignia is placed wrongly, with the feet of the eagle pointing to the front of the collar. The feet should point toward the shoulder side of the collar, as they are the next time we see Potter.
Good-Bye Radar: Part 2 - S8-E5
Other mistake: As the camera cuts to Hawkeye and Margaret working, the man behind her is holding a chest X-ray, but it's upside down, which would be useless as a guide.
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