Goodbye, Farewell, and Amen - S11-E16
Revealing mistake: Col. Potter is taking Sophie to the orphanage at the end of the show. "Sophie" is a male horse. Look closely.
For the Good of the Outfit - S2-E4
Continuity mistake: Henry pops out the golf ball he is washing into the towel. After he finishes talking to Hawkeye, he resumes washing. However, no ball is missing from the dirty pile. (00:02:45)
Revealing mistake: When the tent roof caves in and the projector shorts out in a gush of water from above, you can see that actually the projector "shorts out" before the tent roof ruptures. The crew probably didn't want to risk the pyrotechnic devices getting wet. (00:02:25)
Audio problem: At the end, while Radar is playing drums, he is using drumsticks but drum brushes are heard.
Revealing mistake: Anytime Margaret and Hawkeye are drinking in the bar, there is no liquid in the bottles.
Sometimes You Hear the Bullet - S1-E17
Continuity mistake: Hawkeye lifts Wendell's arm, takes his pulse and lays his arm down by his side again. In the next shot, Wendell's arm is across his chest. (00:13:55)
Continuity mistake: When Margaret pins on Frank's purple heart, his scrubs are very damp with sweat. When he enters the swamp, they're practically dry. (00:03:50)
Revealing mistake: When Hawkeye exits the tub, you can see his shorts as he wraps the towel around himself.
Sometimes You Hear the Bullet - S1-E17
Continuity mistake: As Frank receives his purple heart, Henry calls him 'Franklin D. Burns' All other references to his full name in the series give his middle name as 'Marion'. (00:23:50)
Continuity mistake: Charles (in scrubs), Radar, and Father Mulchahy are all in the changing room when Radar and Mulchahy go take a phone call. When entering the comm room, Charles has appeared and is complaining about waiting for a phone call in his fatigues.
Continuity mistake: After Hawkeye and Burns drive through the puddle, the mud on the colonel's face is different in the long and closeup shots. (00:02:00)
Revealing mistake: When Frank is digging for gold, he has 2 shadows. (00:20:00)
Other mistake: During the game, when the second bomb goes off, the whole building is shaking and things are falling all around but the drinks on the table do not move at all.
Revealing mistake: When Hawkeye walks into the mess tent naked as per his bet with Trapper, in some shots, you can see that he is really still wearing shorts. (00:07:40)
Continuity mistake: When Margaret arrives from Tokyo, BJ and Hawkeye's squashed orange disappears from the ground. (00:05:35)
Revealing mistake: When Col. Potter is in the helicopter looking for a new site for the camp, you can see landscape reflecting in the canopy. This never changes position although they're meant to be flying around. (00:22:30)
Mad Dogs and Servicemen - S3-E13
Other mistake: Hawkeye, Henry and Trapper are playing scrabble. The board is in an illegal state - in the lower right corner 'it', 'jot', 'joy' 'yearn' and 'in' are not connected to the rest of the words. Since the others call Hawkeye on his non-existant word, I'm assuming they're playing properly. (00:15:35)
Continuity mistake: During the scene which culminates in Frank declaring the camp dry the patches of water on his helmet change position. (00:05:50)
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