Factual error: Radar's mother's boyfriend owns a Nash Metropolitan, a car that was not produced until after the end of the Korean War.
Audio problem: As Roy and Loraine enter the camp, you hear a "YEE-HAW" from Roy, but if you watch his mouth, you see he really says "YAHOO."
Last Laugh - S6-E3
Character mistake: BJ refers to his friend Leo as colonel. He's wearing two silver bars, insignia of a captain.
Change Day - S6-E8
Continuity mistake: From the back, while denying Charles entry, the whistle Klinger has on flips over his left shoulder. A moment later, as Hawkeye and BJ walk up, the whistle is in front.
Audio problem: After Potter convinces Saunders he still wants to live, the hiss from the anesthesia machine fades out even while Potter and Saunders are still standing next to it. Neither Potter nor Saunders turned off the valve again.
Continuity mistake: As Ames is pitched the idea of diet and exercise, he has his fork up with a bite of egg on it. When Hawkeye reaches for the fork, it's upside down and clean.
Revealing mistake: While painting Winchester's portrait, the camera looks across Potter's position. As it does, the picture is totally finished, though Potter acts like he's working on it.
Continuity mistake: Charles and the G.I. lay waiting for an explosion. When the last mortar hits, the explosion is just to the left of the back tire, the jeep is untouched. After a cut, the jeep is trashed and burning.
Continuity mistake: While Charles is reading the letter about his nephew being discharged because of fainting spells, Klinger feigns a fainting spell falling forward onto Hawkeye's cot, and his body lies lopsided with his leg hanging off, but when it cuts to the next shot Klinger's perfectly positioned on the cot. Also, note the mail Klinger tossed earlier onto Hawkeye's cot, near his pillow, is now neatly tucked under the blanket towards the foot of the cot.
Revealing mistake: When Margaret whistles for the "third wave" she places Winchester's French horn on the ground, and there are three shots facing the jeep as it closes in on the horn - in the first two shots the horn's normal, but in the last shot the horn's already semi-squashed before the jeep even runs over it.
Continuity mistake: In the Operating Room, as Charles hears that his phonograph has been "donated" for use during the emergency, he turns his head from left to right. In the close up, he lifts his head.
Continuity mistake: When the Jeep runs over the French horn, the crowd is a good distance back. When Potter comes out and picks up the flattened horn, the crowd is only five or six feet away without having moved up.
Visible crew/equipment: As Hawkeye walks over to the Colonel, there appears to be a lighting rig, or a reflector, over the Colonel's cot in the upper left of the shot. (00:20:35)
The Merchant of Korea - S6-E14
Continuity mistake: After answering a call for help, BJ gets first a right glove on, then as he talks, gets a left glove. After the angle changes, he gets a left glove again.
Continuity mistake: In the last O.R. of the episode, Winchester is wearing a surgical gown with the same blood stain pattern as in the previous episode. This also would be impossible given the cleaning procedures.
Continuity mistake: When the bomb disposal sergeant is sitting down at the end of the episode, he's facing the table. When the camera cuts in closer, his left shoulder is facing the table.
Continuity mistake: When BJ and Hawkeye are arguing while trying to eat, Winchester starts his French Horn. When the camera is behind BJ, he puts down his fork. When the camera cuts to a front shot of BJ, he's holding the fork he just put down. Then the camera cuts to look at Hawkeye, BJ's fork is down again.
Other mistake: In the episode where Radar is talking to Corporal Hendrix, Radar says that he was thinking about getting a tattoo himself. But in season 3 episode 7 when Col. Blake was giving Radar his physical he had an anchor on his right arm which he said was his new tattoo. (00:08:20)
Other mistake: When Penobscot is approaching the group, you can make out "4077 USA MASH" on the bumper, even though the the numbers and MASH are partially obscured.
Patent 4077 - S6-E16
Continuity mistake: When the boys are working on the vascular clamp, Charles brings out three hard boiled eggs. After he heckles BJ and Hawkeye for a minute, BJ takes the hammer, and smashes Charles' eggs. The camera cuts to the boys, and back to Charles. There are now two eggs, and almost intact.