Visible crew/equipment: While Kilnger's guarding Soon-Lee, when Father Mulcahy walks into the tent the shadow of the boom mic dips into view at the top, left side of the screen.
Visible crew/equipment: In the Swamp, when Houlihan shouts, "I'll be back and you better come up with something," the moving shadow of the boom mic can be seen at the top, left side of the screen.
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