As You Were - S2-E20
Character mistake: When Hawkeye asks Frank what he is doing, Frank replies he is lining up all bottles and jars "according to height and popularity". In fact, the bottles are not lined up according to height at all, also the order of condiments is different on the two tables. The sweet and sour gherkins Frank mentions are not there at all - during the pan shots you can see the line ends with the pepper. (00:01:50)
As You Were - S2-E20
Continuity mistake: Hawkeye pulls the blanket over Frank's right arm, then pulls his left arm up to take his pulse. In the following closeup Frank's right arm is uncovered, and the blanket is below the screen. (00:18:45)
As You Were - S2-E20
Revealing mistake: At the end, in the shot of Klinger singing while he's sewing a dress on his White Rotary sewing machine, as he's guiding the fabric forward it isn't actually under the machine's presser foot, which it needs to be in order to be stitched by the needle.
As You Were - S2-E20
Continuity mistake: When Klinger's in Father Mulcahy's tent he pulls up a chair and when he sits down he places his purse on his lap, but in the closeup the purse strap is now around his left arm.
As You Were - S2-E20
Revealing mistake: As Henry goes over to the expectant mother, a round takes out the generator. After the lights go out, there is a blue light outside the window, and also blue lights over the action. They can be seen in the reflections on the light sets over the tables.
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