Continuity mistake: The display behind Klink changes. Sometimes, a map of the area around The Stalag, sometimes a layout of the the Stalag. Also, the picture of Hitler with the microphone bug. Sometimes there, sometimes moved, or gone completely.
Factual error: Throughout the entire series, there are often uniforms that are incorrect; an oversized eagle on German Visor Caps appears most often.
Factual error: Hogan and his men are in Berlin to capture a traitor. They arrive at the Hotel Berlin in an ambulance and park near a K2 phone booth, something only found in England and its colonies, certainly never in the heart of Nazi Germany. (00:13:55)
Character mistake: As Stauffen parts company with Col. Hogan at the road checkpoint, he salutes Hogan. While that is understandable under the circumstances - after all Hogan just saved his life, it would also be highly suspicious. Both Schultz and Stauffen's adjutant were watching them, so it can't be said they did it surreptitiously either. After all, Stauffen is a German general whereas Hogan is an allied prisoner officer of inferior rank. For an officer of higher rank to initiate the salute is a demonstration of great respect and/or thanks, which, as far as anyone besides Stauffen and Hogan knew, was not warranted in this situation.
Continuity mistake: Throughout the whole series, the guys access the tunnels through a trapdoor built into the bunk closest to what appears to be the east end of the barracks. What is interesting is the method used to make the trapdoor open and the bunk rise. sometimes, it's two taps, two slaps, or two pushes of a "key", a panel that's made to look like the side of the bunk.
Klink vs. the Gonculator - S4-E2
Continuity mistake: In the barracks, as Lutz stands by the gonculator, Hogan's hand toys with the power cord. A second later, both his hands are at his sides.
Hogan Gives a Birthday Party - S2-E1
Continuity mistake: Hogan Gives a Birthday Party when the prisoners capture a German plane. When it is taking off, it is an English Lancaster bomber with a twin tail. As it is flying overhead, it is an American B-17 with a single tail. Finally as it is shown flying, it is a German FW-200 maritime bomber.
Continuity mistake: Hogan is listed as being from different places throughout the series; e.g., Ohio, Bridgeport, Connecticut, Indianapolis, etc.
The Late Inspector General - S1-E4
Plot hole: At the beginning, the Inspector General instantly pegs the incidents Hogan's men enact as staged to defame Klink, and takes it as proof Klink is the right man to be put in charge of all POW camps in the Reich. Later, as Klink and he do their "final inspection", much less severe - and frankly, much less believable - incidents cause him to completely revise his assessment of Klink. Him believing Klink would be a pickpocket and compulsive kleptomaniac simply doesn't make sense.
Deliberate mistake: The film crew did not always bother to switch out the rank insignia on the uniforms of extras. In this episode, that leads to all kinds of enlisted and noncom rank insignia being present in the lineup of brand-new recruits when Klink inspects them. Rightfully they should all wear a single eagle on a borderless patch of a Flieger on their collar.
Other mistake: The scene in Klink's quarters is one of a few where you can see Larry Hovis' (Carter) wedding ring.
Continuity mistake: After Hogan, LeBeau, and Newkirk leave, Carter is sitting, holding the glass with both hands. After the cut, he's holding the glass in his right hand only.
Continuity mistake: When Hogan and the crew first see the silent airplane overhead, it has a twin tail. When shown up close in later scenes it has a single tail.
Continuity mistake: After getting Crittendon to turn around, Hogan grabs his hat with his right hand. When the camera looks at Hogan, he's pulling his left hand back, holding his hat.
Some of Their Planes Are Missing - S3-E2
Visible crew/equipment: When LeBeau, Carter and Schultz enter the visiting Germans' quarters, when the door is open you can see the sound stage floorboards are uneven in front of the door to the neighbouring barracks.
Two Nazis for the Price of One - S3-E17
Continuity mistake: Freitag is shot at night, but when Hogan goes outside and talks to his men it's daytime.
Everybody Loves a Snowman - S3-E14
Revealing mistake: As the sink with the fake tunnel is prepared, just before Newkirk goes over to set things up, you can see movement through a crack in the door. It's Schultz, Hochstetter, and Klink, waiting their cue to enter.
Continuity mistake: After Hogan leaves the airman in the tree, LeBeau jumps down, and looks up to tell the man it will be OK. When the camera looks at the man, you see LeBeau's legs and feet behind him.
Top Hat, White Tie and Bomb Sights - S1-E10
Audio problem: As Schultz is complaining about Klink, Hogan puts his hand over Schultz's mouth, and you start to hear the canned laughter. When the camera looks at Klink, the sound Schultz made with the canned laughter behind it is repeated.
Request Permission to Escape - S1-E32
Other mistake: Carter is washing things in front of the barracks. There is snow on the ground and on the windowsills and they are wearing winter jackets but the cold weather doesn't bother him putting his hands in the water over and over. He even gets splashed in the face but it doesn't faze him.
Answer: It's a solitary cell. Steve McQueen, star of 'The Great Escape' is known as the 'Cooler King'.