Nights in Shining Armor - S3-E8
Factual error: When the prisoners are in the workshop to "fix" the plumbing, sergeant Shultz is armed with a krag Jorgensen rifle. German soldiers were armed with the k98 mauser, not the krag.
Nights in Shining Armor - S3-E8
Other mistake: When Hogan shoots the vest, it stays still for a couple of seconds then swings in a way that is not normal.
Nights in Shining Armor - S3-E8
Other mistake: In Hogan's quarters, after Hogan reveals the two Aces up Newkirk's sleeve, Newkirk goes to brush his hair. As his hand goes up, you can see the cards in his hand.
Nights in Shining Armor - S3-E8
Other mistake: In the end, Schultz tests the faucets, and they work correctly. When Klink goes to touch the faucets, watch the drain. The high pressure jet of water comes from it just when Klink is over it.
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