Continuity mistake: As Hawkeye talks to the North Koren, the Korean has his hand across his lap. A second later, his arm is up, with his fingers on his temple.
Plot hole: This episode revolves around the doctors trying to "transfer" a north Korean surgeon to the outfit. To this end, they get him papers, uniform, dog tags, etc. In the end, the plot is toppled and The Korean Surgeon taken to a POW camp by the MP. In reality, it would not have ended quite so pleasantly. A combatant wearing the uniform of an enemy is usually automatically considered a spy, and Hawkeye, BJ and Radar would also have been considered guilty of espionage or at least complicity therein.
Continuity mistake: In the beginning of the episode Colonel Potter is painting a portrait of Hawkeye with his feet up, and Klinger's picture is hanging to the right of the door. But in the previous episode 'Korean surgeon' Klinger's portrait is on the left side of the door and the one of Hawkeye's is on the right side of the door, even though that portrait wasn't painted until the following episode. (00:03:15 - 00:17:55)
Continuity mistake: In the beginning, Colonel Potter is painting a portrait of Hawkeye. In the preceding episode, The Korean Surgeon, the painting is finished and hanging on the wall in Colonel Potter's office. It is hanging just to the left of the door. The time given is from The Korean Surgeon where you can see the painting hanging on the wall. (00:17:05)
Character mistake: After Potter mocks Hawkeye for not hitting anything, Hawkeye replies "You fired as many shots as I did". In fact, Potter fired seven shots, Hawkeye only five. On a side note, this also suggests that Hawkeye probably was supposed to fire seven times, but his weapon jammed after the fifth shot. (00:22:00)
Visible crew/equipment: As Potter and Hawkeye look at the totalled and burning jeep, the shadow of the camera's shade can be seen at the lower left corner of the shot.
Character mistake: As Potter and Hawkeye pull up to the MP checkpoint, Potter and the MP exchange salutes. As per Army regulations, no salutes are given under battle conditions. The reason is that if the superior officer, in this case Colonel Potter, returns the salute, he can be a target for snipers.
Factual error: While on the phone, Radar spells out BJ's father-in-law's last name, "H-A-Y-D-E-N" to which Hawkeye quips, "M-O-U-S-E" parodying the old line from the Mickey Mouse club. The M.M. club didn't air until 1955.
Continuity mistake: As the discussion about Burns draws to a close, Potter starts to grab the files on his desk. As he says "Dismissed", he grabs them again.
Continuity mistake: From the back, Potter is facing directly at Hawkeye and BJ. From the front, he's in quarter profile, left side forward.
Continuity mistake: As BJ mentions fingernails on a chalkboard, Potter hunches his shoulders up. A second later, after the angle changes, he repeats the action.
Continuity mistake: In this episode, a "Spirit Post" is placed in the middle of the compound, later removed, then replaced at the end of the episode. It is never seen again after that.
Suggested correction: It was probably left behind during one of the bug outs that happen. We have seen at least 2 in the series.
The Most Unforgettable Characters - S5-E14
Other mistake: After Klinger douses himself with real gas (Potter determined that Klinger's can only had water in it, and told Radar to switch the can for real gas), and runs into the shower tent, you hear a nurse scream, and see her run out. When the door is open, there are no stalls to be seen. From all scenes shot inside the tent, you know that the stalls are big enough to be easily seen from the outside.
Other mistake: When Hawkeye finds the New York Times Crossword he says, "1 down, four letters..." and "1 across...four letters..." and BJ's answers are "chap" and "cast" but in the shot of the newspaper puzzle we see that both "1 down" and "1 across" are actually five letters each, not four.
Revealing mistake: Klinger makes a big show of removing a big nut from the Jeep's leaf spring. The nut is clean and shiny whereas the rest of the undercarriage is painted and dirty. If you look closely, there are no screw threads where he takes it off either, there's another hex under it. The simple reason for this is that that nut doesn't belong there and never was affixed, Jamie Farr just pretended it was.
Continuity mistake: After Radar leaves the message with Stevens for Hawkeye's friend on the Essex, it cuts to Klinger removing a nut from the jeep and he's holding the wrench with his thumb at the top, but next shot he's holding the wrench the opposite way.
Factual error: When BJ and Hawkeye go to Potter to talk about Cho Lin wanting to get married at the 4077th, Potter mentions he expects to be home in Nebraska in 16 months, three weeks and four days when they try to fool Potter about Cho Lin. Potter has always said he and his family live in Missouri, however.
Revealing mistake: In the mess, you can see everyone has their food on metal trays and ceramic dishes. Sgt Zale, though, has his lemon pie in a polystyrene dish - so that it doesn't hurt Klinger when he gets it in the face. (00:08:15)
Audio problem: During the fight in Rosie's bar, a soldier is punched, and then thrown through the opaque window with the wood frame behind him. There is a sound of breaking glass accompanying the motion, but you can see the torn paper.
