Continuity mistake: Along with Radar holding an anachronistic comic book (the Avengers), the exact issue changes between wide and close shots. One has the older Avengers logo used in the '60s and very early '70s, while the second issue Radar is holding has the newer Avengers logo that just gained currency as the episode was being filmed. (00:00:45)
Continuity mistake: Early in the episode it is stated that Margaret's tent door is padlocked while she is in Tokyo. But when she gets back, she just walks straight in. (00:22:20)
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