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.
Audio problem: When the bulb in the projector goes out, Klinger is trying to fix it. People throw popcorn at him, saying "Find it!" After Potter says "Hit it, Father!", watch Klinger. From the wide shot to the close up, you hear him say "The bulb is hot!", but his lips don't move.
Factual error: The MP describes the antique vase Burns is supposed to have bought as "An 800-year-old seladon vase of the Ko-Yu dynasty". Later, Burns packs up a white vase to send to his wife. Seladon is by definition green, and that kind of color glazing definitely wasn't around in the 13th century. What Burns packs up looks most like early to middle Quing period - or rather a contemporary ripoff. (00:09:00 - 00:14:00)
Continuity mistake: When Hawkeye and BJ unload the chopper, the dog, Corp. Cupcake, is lying on its paws in the long shots and on its side in the closeups. (00:03:35)
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)
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.
The Abduction of Margaret Houlihan - S5-E6
Other mistake: As Frank cocks his gun in the Swamp, the slide locks open and he has to hit the slide release to get it to move forward. Next he fiddles with the hammer. Next we hear the shot go off. Burns' excuse later is that he was cleaning The Gun and it went off (although admittedly, Frank doesn't always stick to the truth that religiously in situations like that). The slide on a semi-automatic locks open only if the magazine is empty or missing. The Gun locking open is also a clear, unmistakable indication that the breech is empty. He would have to insert a filled mag, then pull the slide back again to chamber a round before The Gun even had the chance to go off. One never does that while cleaning a gun. One does what Frank did to begin with: Pull the slide back without a magazine inserted to make sure the breech is empty.
Suggested correction: Frank has demonstrated on numerous occasions that he does not follow the rules of safe gun handling, so ascribing his failure to do so is not a mistake.
You are missing the point. His gun is demonstrably unloaded when we last see it. He would either have to change his mind about cleaning it and load it instead, or load it first and then try to clean it (which makes even less sense), neither of which is not supported by anything in the dialogue.
Character mistake: At the end of the episode, while Col. Potter is in the helicopter asking where they are, the pilot says they are about 10 miles west of Inchon. Col. Potter says this is no good and he tells the chopper pilot to "head west, towards Inchon." If they are already west of Inchon, heading west will take them further from Inchon.
Suggested correction: Potter tells the pilot to head to a different city, Chuksan (not sure of its spelling).
Visible crew/equipment: As Margaret gets into the chopper, the lighting rigs, camera and crew are reflected in the canopy.
The General's Practitioner - S5-E20
Visible crew/equipment: When the Colonel that Hawkeye referred to as "Bozo" is talking to General Korso on the way to the 4077th to get Hawkeye, you can see the shadow of the camera on the Colonel's lap.
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.
Continuity mistake: After a distant aerial shot of Potter's chopper, the camera closes in for a close up. When in the distance, the rotors are running full speed. In the close up, they are barely running, just enough to make the familiar whooshing sound. The chopper that they are in is being raised and lowered to simulate flight. Also, if you look in the canopy in front of Potter, you can see the camera and crew's reflection. Then when the chopper is over the building, the sound of the blades is still the slow moving whooshing mentioned earlier, instead of the full power sound it should be.
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.