Praise the Fuhrer and Pass the Ammunition - S2-E19
Continuity mistake: As Newkirk leaves the stage to do his "hat trick", his sweater is clean. When doing the trick, there are stains on the sweater before he starts.
Visible crew/equipment: After Hogan, Le Beau and Schultz get into the car, and as it starts to move, chairs, people and equipment are reflected on the glass.
Visible crew/equipment: As the General gets in his staff car and it leaves, the film crew and equipment are reflected on the sides.
Audio problem: The top of the coffee pot is on the basket rather than open, but we can hear the conversation.
Continuity mistake: As the general comes into Klink's office, Carter pours another cup of coffee, and starts to put the pot down. A second later, he's putting it down again.
Continuity mistake: During Carter's second meal, the napkin in his shirt comes loose and starts to fall. A second later, it's firmly in place in his shirt.
A Klink, a Bomb and a Short Fuse - S2-E8
Continuity mistake: Newkirk comes out of Klink's office with a code book, and passes it to Le Beau, who immediately holds it up and opens it. In the close up, Carter's hands bring up a book with a camera in it, and Le Beau brings the book out from his back and opens it again.
Request Permission to Escape - S1-E32
Continuity mistake: As Schultz starts to wet Klink, several big spots appear on the left of Schultz's jacket, then disappear a moment later.
How to Cook a German Goose by Radar - S1-E24
Continuity mistake: As Tillman starts to talk to Hogan, he places his hand on, then removes, it from, Hogan's arm. A second later, he repeats removing his hand.
Other mistake: After talking to the officers in the Höfbräu, the scene shifts to a closed business with Hogan talking to the waitress. As it shifts, the cameraman accidentally shakes the camera.
Continuity mistake: When Newkirk calls "Heil Hitler", everyone in the lobby salutes. A second later, in the closeup of Hogan and Newkirk, everyone's arms are suddenly back by their sides, much too quickly to be real.
Factual error: In this episode, the HofBrau (which should correctly be written "Hofbräu") is displaying a big red neon sign above its door. From 1939 on, air raid regulations throughout Germany strictly prohibited any unnecessary display of light at night. Any light visible from more than 500m away was considered a breach of air raid regulations.
The Great Brinksmeyer Robbery - S2-E18
Factual error: In the restaurant in Hammelburg, where Schultz discovers Hogan and Newkirk, there's an advertisement for "Brauerei der Jager, Stadt Wien." (Wien = Vienna) Vienna and Hammelburg are more than 500km apart, and if Hammelburg were near Düsseldorf, where the series puts it, it would be more like 700km. That's a bit far away for a brewery to advertise in the pre-globalisation era.
Is There a Doctor in the House? - S3-E18
Revealing mistake: As Carter blows into the bottom of the oven, the suds that hit Newkirk in the face come out in a thin stream on top, not out of the whole stovepipe.
Crittendon's Commandos - S5-E25
Character mistake: To have an excuse not to start up the truck motor, Schultz claims his driver's license has expired. German driver's licenses don't expire.
Clearance Sale at the Black Market - S4-E1
Character mistake: When Hogan addresses him, Major Kiegel sends the girls away from his table by saying "Raus!" The word "raus" used as an imperative literally means "out" in the sense of "leave the room" - he would be ordering the girls to leave the tavern, or at least the tap room in this case. It's not correct German to use it to send somebody away from a table.
Factual error: In several episodes, Hogan's men communicate by radio with a British submarine, and the dialog hints that the sub is submerged at the time. During the WWII era, submarines could not communicate by radio without surfacing first. In most episodes one might argue that the sub could be running shallow with a mast up, which would perhaps be within the technical possibilities of the era, but in this episode, the sub is talking to Hogan's men while under attack by a destroyer. This pretty much rules out running at periscope depth, because ramming was regularly-used tactic for killing subs that were in the process of diving or surfacing. To avoid confusion: Nowadays, subs can communicate while running several hundred feet deep by using VLF and ELF. However, these are definitely not capable of transmitting voice, but are text-only.
Audio problem: In several episodes, e.g. S1E31, German police sirens are heard to underline the impending arrival of Gestapo or other police officers. In each occurrence, the sample used has a distinct Doppler effect. Doppler effect in a sound occurs only if a vehicle passes by the listener at high speed, not when a vehicle approaches a place directly and stops.
Guess Who Came to Dinner? - S4-E9
Factual error: Schultz says, Von Grubner has "a castle right next to the Führer's in Berchtesgaden." Hitler's famous real estate in Obersalzberg wasn't a castle but a mountain chalet based on a former farm estate called the "Steinhaus".
Guess Who Came to Dinner? - S4-E9
Audio problem: When Hogan says "Why is it you can only trust short, dumpy spies?" the movement of his lips does not match the words.
Answer: Nimrod's actual identity was never revealed in the series. It was only known that he was a British intelligence agent. Nimrod was not Colonel Klink. Hogan had only implied it was him as a ruse to get Klink returned as camp commandant, not wanting him replaced by someone more competent who would impede the Heroes war activities. The term "nimrod" is also slang for a nerdy, doofus type of person, though it's unclear why that was his code name.
raywest ★
"Nimrod" is originally a king and hero mentioned in the Tanach and taken into the Bible and the Koran. His name is often used in the sense of "stalker," "hunter," and sometimes figuratively as "womanizer" as in "hunter of women." I've never seen it used to denote a nerdy person, and although I cannot disprove that connotation, I think given his role, the traditional meaning is more likely the intended one.
Doc ★
It's widespread enough that Wikipedia has an entire section on it: https://en.wikipedia.org/wiki/Nimrod#In_popular_culture