Continuity mistake: As Schultz marches in with the Kraut platoon, he reports to Klink. As he goes to stand at attention and report, the new tunnel section he's over collapses, and he completely disappears into the hole. The camera goes to a close up on Klink, then back to the hole, and you see Schultz standing in the hole and it's only chest deep.
Continuity mistake: Notice the jacket that Carter always wears. It always appears worn with age and use. This episode, it appears almost new.
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.
Other mistake: When the man goes to close the door, Newkirk gets a piece of plastic in between the door and the jamb to prevent the lock from engaging. But if you look closely, the plastic is above the lock, not stopping anything.
Hogan and the Lady Doctor - S2-E20
Factual error: The truck used to transport the female doctor to the laboratory, which is also driven by Hogan's team, is a right-hand drive vehicle. Germany used left-hand drive vehicles in WW2 because they drove on the right side of the road. (00:18:02 - 00:22:48)
Klink for the Defense - S6-E19
Factual error: About 9 minutes in, Hochstater asks how long Hogan has been running this camp. Schultz responds, "3 years this November." The earliest Hogan could have been taken prisoner would be December '41, so it would have to be November '42 at the earliest, making it just before November '45. The war in Europe was over in May '45.
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.
Answer: It's a solitary cell. Steve McQueen, star of 'The Great Escape' is known as the 'Cooler King'.