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.
Deliberate mistake: When Flagg turns out the light to escape.To make that effect they had to freeze a frame and then start again. If you look closely after Flagg turns out the light you can see Hawkeye and the Korean Man on the far right freeze. Then it shows Potter ordering the light back on.
Continuity mistake: In one of the earlier episodes Henry becomes the father of a baby boy; his other two children have been established as Molly and Janey, both girls. In "Abyssinia Henry," Henry get his discharge papers and wanted to call home with the good news. He tells Radar that he will have to wait a while, as his son, Andrew, will be practising his trombone. As Henry only has one son, Andrew has to be the son who was born while Henry was in Korea. Even if Henry was in Korea from the very first days of the war, by the time he left his son can't be any older than 18 months - hardly likely to be playing a trombone.
Continuity mistake: When the chopper carrying the soldier with the wounded back takes off, the sky is cloudy and, even accounting for the poor quality of the film, the weather looks very dull. The shot changes to show Radar, Hawkeye and Margaret watching the chopper leave and it is now bright sunshine.
Other mistake: Wendel, afraid of being shipped home, is trying to escape from the MASH by hot-wiring a Jeep. Despite just having had an appendectomy, he is leaning forward and to the right from a sitting position, which would have to put pressure directly on the incision, yet when discovered by Hawkeye, he easily and without discomfort sits up straight. Aside from him still being at the MASH, we know the surgery is recent because, just a little later, he winces and complains after making a very small movement.
Continuity mistake: Charles enters Col. Potter's quarters while Potter is sleeping. Potter sits up in bed while Charles whines and complains about his sister's engagement. In all the shots facing Potter, the hair at the top of his head is very messy and pointing up. In every shot facing Charles, Potter's hair is normal.
Add timeSuper Grover
Deliberate mistake: With the show having lasted longer than the war, the producers apparently decided to turn back the clock to the very beginning of the War (June 25, 1950). To do this, it seems they have tried to make things as confusing as possible, intentionally mixing up facts, even when this openly contradicts the facts as presented in earlier episodes. For example, both B.J. and Potter arrived in or about mid 1952, but now are in the O.R. when the Chinese launch their massive offensive on 1st Nov. 1950, almost two years earlier. Trapper and Blake, who were there for the Army Navy Game which would have occurred Nov. 25 1950, are not. Many of the supporting clips also are too early or late for the events being discussed. For example, Winston Churchill's speech must have been before August 28 when the first British troops started arriving, likely also before the Canadians in July 1950, but the first MASH Unit was not set up in Korea until September 1950. Truman's speech to University of Wyoming students is actually from May 9 1950, a month and a half before the beginning of the conflict and 5 months before the first MASH was established, but the clip about his "Whistle Stop Tour" must be from the 1948 campaign. MacArthur's speech, on the other hand, is in response to the ticker tape parade of April 22 1951 when he was replaced.
Visible crew/equipment: While Klinger is on the phone trying to set up BJ's transportation home, just as Winchester walks into the office pointing out the company clerk the shadow of the moving boom can be seen on the wall, and it's also visible when Winchester takes the mailbag and dumps the contents.
Continuity mistake: After Klinger presses Potter about getting rid of the tank Potter tells Klinger to act like a sergeant, and in the shot from Potter's office Klinger walks out with both of his helmet straps hanging loose, but when it cuts to him walking into the outer office one of the straps is suddenly gone.
Continuity mistake: When Father Mulcahy releases the locked up POWs, in the following explosion Father Mulcahy is knocked to the ground and his eyeglasses are still on his face properly, but in the next shot when BJ rushes to his side the eyeglasses are on the ground behind Mulcahy's head, and BJ did not remove them.
Add timeSuper Grover
Factual error: During this episode, Sergent Klinger gives a Hershey Chocolate Bar with Almonds (although the 'Hershey' name is obliterated on the bulk box as well as the bar itself, there is no doubt as to what it is) to a wounded North Korean soldier, who accepts it and turns it upside down, revealing a Universal Product Code bar code. Bar codes were not used on products until some 20 years later.
Visible crew/equipment: When Klinger's at Little Chicago he asks one of the black market vendors about cameras and he points to another vendor, and when it cuts to the next shot we can see the actor's T-mark on the ground where the man walks away (his foot even moves the T-mark) and Klinger is about to stand.
Add timeSuper Grover