Character mistake: The last bet comes to Frank after Mulcahy bets a dollar, and Potter raises fifty cents, making it a dollar fifty. Frank makes it another five dollars, making it six dollars fifty cents. Mulcahy says "Oh dear, it's five fifty to me." He should have said six fifty.
Dear Peggy - S4-E10
Character mistake: When he sees the 'P' for Protestant on Davis' chart, Col. Hollister states "A lot of your Davises are 'J's, you know" implying that Davis is a Jewish name. In fact, the ID tag code for Jewish faith was 'H' for Hebrew. (00:18:45)
Character mistake: When Frank is berating Igor about the food on the trays, he calls him "Sergeant." Igor has always been a private.
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