Continuity mistake: After uncovering the motorcycle, there's only the tan chicken around. A moment later, Ralph has a brown chicken in his arm that wasn't there before.
Continuity mistake: As "Ralph" gets the chicken off the tarp covered motorcycle, he goes to pick up the egg with his left hand. After the close up, he does it with his right.
Visible crew/equipment: As Hawkeye, BJ, and "Ralph" come over to help the farmer, the shadow of the boom mic is on the ground at the bottom right side of the shot.
Continuity mistake: When "Ralph" has Hawkeye and BJ at gunpoint, saving their lives, the scenery behind them changes several times. Sometimes there's the road and a few trees. Then there's no road and a lot more trees and shrubbery.
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