Factual error: In one episode in the hospital tent, Hawkeye hands a Hershey Chocolate Bar to a wounded soldier lying in bed. The back of the candy bar had a Universal Product Code (UPC) on it. UPCs were not used until the 1970s.
Factual error: Throughout the series, actors are seen wearing cuffless permapress fatigues. Neither cuffless nor permapress utilities were available until the 1970s.
Factual error: Throughout the series, there are repeated instances of "I Corps" being pronounced, "Eye Corps." Since Army corps are designated by Roman numerals, it should be pronounced, "First Corps." (I wonder how they would have pronounced "III Corps" or "XVII Corps?").
Factual error: Nearly every show depicts the use of disposable plastic syringes, which weren't introduced till 1955, two years after the war ended.
Factual error: The Spot-A-Card pinball machine in the Officers' Club didn't come out until the 60's.
Factual error: In the Swamp, Frank is complaining about everything, and goes to grab the still. The stove it's sitting on is a Coleman model 413E camping stove, a unit not seen until 1954, and the series takes place in 1950.
Factual error: Hawkeye and Trapper are concerned about the theft of a stock of hydrocortisone, but that drug wasn't introduced by the FDA until 1952.
Sometimes You Hear the Bullet - S1-E17
Factual error: We see Pvt. Wendel trying to hot-wire a jeep to escape. He wouldn't have to hot-wire it, because vehicles assigned to a combat zone were equipped with an ignition switch, not an ignition lock, for the simple reason that keys get lost or mislaid all the time and in an emergency, having to track down keys for vehicles would be extremely detrimental to an unit's combat effectiveness.
Factual error: The announcer says that it will be the 53rd Army-Navy game, but the game has been played every year since 1890, with no games in the years 1894-98, 1909, 1917-18, and 1928-29, so this game would be number 51. Additionally, at the end of the episode we find out the result was Navy 42 - Army 36. While Navy won all three games during the Korean conflict, none of those games ended with such a score. The score in the 1950 game was 14-2.
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.
Suggested correction: While that is true by the Army's standards, it is entirely in character for Hawkeye not to give a flying you-know-what about the state of his insignia.
True, but even he knew that correcting it sooner rather than later would be wise. But, as always, I bow to your knowledge.
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.
Factual error: When Frank sits down on Margaret's bed, he pulls a single metal star out of his butt. Kelly being a Lt. Gen, he should have (and has, as can be seen in other scenes) a single bar of three interconnected stars, not three single ones. Therefore Frank shouldn't be able to find a solitary star in Margaret's bed. (00:19:00)
Factual error: Radar gives the location of the battle as Longitude 70, Latitude 27. This means the Korean war has spread to India. (00:21:00)
Springtime - S3-E6
Factual error: Radar mentions to a nurse he's smitten with that the movie that night is "Firstborn of Godzilla." Godzilla (the movie, not the monster) wasn't released until 1954. (00:15:10)
Factual error: Another premature mention of Godzilla when Col. Blake announces that night's movie, "Godzilla and the Bobby Soxer". (00:01:57)