Factual error: Out by The Gun, Hawkeye's Captain insignia on his garrison cap is missing the lower corner of one bar. So, it would be considered unserviceable, that is, unfit for use, and should have been replaced with a new insignia.
Factual error: General Clayton is wearing ribbons on his regular fatigues. This is incorrect as the ribbons would only be displayed on the dress uniforms. Only the officer's rank would be on the fatigues.
Factual error: Radar claims in his report that Father Mulchahy tried to calm the prisoner by saying "bang zhao", thinking it means "peace and friendship" when it really means "your daughter's pregnancy brings much joy to our village." There is, unsurprisingly, not even a remotely similar word in Chinese that means either of those things.
For the Good of the Outfit - S2-E4
Factual error: During Henry Blake's command, a model of a Bell UH-1 'Huey' can be seen hanging from the ceiling of the commander's office in several shots. In fact, the Huey's first flight was only in 1956.
Factual error: The Logan Ramsey character tells Hawkeye and Trapper that with enough notice he could get them anything, even a B-52. The first B-52A entered service in 1954, a year after the Korean War ended.
Deal Me Out - S2-E13
Factual error: In this episode, Henry is seen handing Radar the keys to his jeep. While this probably benefited the understanding of the audience, it is historically incorrect. Jeeps assigned to a combat zone were outfitted with an ignition switch, not an ignition lock, for the simple reason that in an emergency the vehicle had to be useable by anyone. (00:03:40)
Factual error: In surgery Trapper John is singing Frank Sinatra's version of "I got you under my skin". Although it was written in 1936, Sinatra did not release it until 1956, after the Korean War ended. The 1936 version sung by Al Bowlly sounds nothing like the version Trapper John was singing, which was mimicking Sinatra's version.
Suggested correction: While it hadn't been released on vinyl until 1956, Sinatra had sung the song as early as 1946 on his radio show and during live shows.
The version Frank Sinatra sang on his radio show was similar to the original version used in the movie "Born to Dance" (a movie he references before singing his two songs). He didn't change it to the big band version that Trapper imitates until 1956.
