Continuity mistake: The psychiatrist is called Milton Freedman in this episode and Sydney Freedman in all other episodes in which he appears (always being played by the same actor - it is the same psychiatrist).
Continuity mistake: When Hawkeye and Lt. Johnson are sharing Hawkeye's bottle of "wine" there's a closeup of Johnson's hand holding the glass, and in the closeup that hand has short nails, whereas in all other shots Johnson has long nails.
Continuity mistake: When Trapper and Hawkeye are sitting outside the Swamp, Hawkeye pours the martinis from the tall glass beaker, and in the shots facing Hawkeye there are quite a few large ice cubes in the beaker, but in the shots facing Trapper there aren't as many ice cubes floating in the beaker.
Continuity mistake: The amount of alcohol in the bottle Hawkeye holds in the Swamp goes from full to half empty and back between cuts.
Continuity mistake: When Hawkeye passes by Frank on his way to Lt. Johnson's, he's holding a bottle of gin up near his waist. In the next shot, his arm is resting down by his side. (00:08:30)
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