Father's Day - S9-E4
Continuity mistake: As Margaret sits on the bunk to talk with Al, his hands are by the table's edge. When the angle changes, they're up at chin level.
Continuity mistake: When Maj. Winchester hears that the Giants won, he drops his baseball cap. A few shots later we see him lying on his back, clasping his cap in his hand.
Tell It to the Marines - S9-E8
Continuity mistake: The water Klinger accidentally spits on Potter goes from a number of separate spots to one big spot in a couple of seconds.
Tell It to the Marines - S9-E8
Continuity mistake: In the mess tent, after Hawkeye and BJ read about the blood donations, Hawkeye goes to fold and put the paper down. When the camera cuts to a wide shot, he's folding and putting the paper down again.
Continuity mistake: While BJ, Hawkeye, and Margaret are in the OR, BJ has the stethoscope either around his neck or the eartips are in his ears, depending on the angle of the consecutive shots.
Continuity mistake: While Charles, BJ, and Hawkeye are in the Officers' Club, when Margaret storms in and starts yelling at Charles about the visiting pervert Colonel, Charles facepalms himself with his right hand, but next shot his left hand is up, and it continues to switch.
Continuity mistake: As Charles talks to Finch, he hangs up the clipboard, and puts the pencil in his pocket. Then as he turns Finch to walk out, he puts the pencil in his pocket again.
Continuity mistake: In the Officer's Club, Potter is about to order a drink. When he goes to give the order, he starts to look at Hawkeye. When the camera cuts to a close up of Potter, Hawkeye, and BJ, he's facing forward again.
Continuity mistake: As Mulcahy enters and is introduced by Potter, he assumes the podium, and clasps his hands behind his back. A second later, his arms are by his sides.
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