Man's Best Friend Is Not His Dog - S4-E6
Revealing mistake: As Schultz holds Newkirk's hat during the search, you can see "Dawson" written on the inside band. This was to insure that Richard Dawson (Newkirk) always had the right wardrobe pieces.
Man's Best Friend Is Not His Dog - S4-E6
Factual error: When Hogan heads into Klink's flower bed to get the dog, you can see a modern steel water tank in the distance.
Man's Best Friend Is Not His Dog - S4-E6
Continuity mistake: The dog LeBeau is holding shifts position on his arm with each camera change.
Man's Best Friend Is Not His Dog - S4-E6
Other mistake: When seeing the tanks through the viewfinder, Carter's hands and the background are frozen, and the tanks are actually a clip of a wartime newsreel.
Man's Best Friend Is Not His Dog - S4-E6
Continuity mistake: Hogan's arms change position when holding the dog. First, his left is under the dog, and after the angle change, his right is under the dog.
Man's Best Friend Is Not His Dog - S4-E6
Other mistake: When referring to the barracks, usually Klink will refer to the buildings by their numbers (Barracks 2, barracks 3, etc.). In this episode, he calls the building "Building G".
Never Play Cards with Strangers - S4-E7
Other mistake: As Carter brings the German truck to a rough stop, in the closeup, you can see that although Carter and Newkirk lurch in the seats, the truck was already motionless.
Never Play Cards with Strangers - S4-E7
Visible crew/equipment: As Hogan takes off with Von Treger's car, the camera crew and equipment are reflected in the windows.
Color the Luftwaffe Red - S4-E8
Factual error: The medal Newkirk steals from the German officer in the pub is a Knight's Cross of the Iron Cross with Oak Leaves and Swords. There were a total of 148 presentations, most of them 1943-45. By 1942 (where the series is apparently set), less than 25 had been presented. That Newkirk should actually stumble across a wearer by pure chance is highly unlikely, that the wearer should actually "never miss it" as Newkirk states, is plainly impossible. Being the fourth highest ranking military decoration of the Wehrmacht, it would have been missed almost immediately - if not by the wearer himself, then by his fellow officers. (00:22:35)
Color the Luftwaffe Red - S4-E8
Revealing mistake: When the truck with Hogan and company pulls up to the Luftwaffe HQ, the camera pans to the right to look at Klink getting out of the side car. When the camera cuts back to Hogan and company, they shake as if the truck just stopped, but it can be seen that the truck was stationary.
Color the Luftwaffe Red - S4-E8
Other mistake: The telephone booth located by the Luftwaffe HQ appears to be one of the London police boxes.
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.
Continuity mistake: In Klink's quarters, Hogan is complaining about Berger's activities. As he does, he goes to eat a sandwich with his left hand. After the angle change, he has both hands on it.
Continuity mistake: When a German Major is in Col Hogan's quarters he is wearing black leather gloves. He raises his hand to remove his hat (with gloves). Next scene he is lowering his hat with bare hands. (00:02:10)
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)
Factual error: The ambulance Major Teppel transports the prisoners in is a Dodge WC54, which is an American military ambulance, not a German one.
Other mistake: As LeBeau is being interrogated, on the barometer behind Schultz you can make out the word "fair." What is a barometer labeled in English doing in a German counter-intelligence headquarters?
Continuity mistake: As Major Tepple (Morrison) lays the deck of cards in Hogan's room on the table, the bottom card is not neatly in the deck. When the camera cuts to another angle, the deck is neatly stacked.
Continuity mistake: As the ambulance leaves the hotel, there is snow on top of the fenders and spare tire. Back at the truck, there is snow on the fenders, but not the spare. This would be impossible as at the speed driven, the snow would have blown off any horizontal surface.
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