How to Cook a German Goose by Radar - S1-E24
Revealing mistake: Toward the end of the episode, a guard is watching Helga posing in a one piece bikini for Lebeau. As you look past him, you see only blue screen, no view of the surrounding property. Same when Hogan climbs up, you don't see the tops of buildings; you can tell it's on a soundstage.
How to Cook a German Goose by Radar - S1-E24
Revealing mistake: After Hogan and the boys decide to get rid of Tillman, they "accidentally" set fire to the trash can on the Kommandant's porch. To that end they load up a bunch of trash that's been soaked in gas. Then Hogan tosses a lit match in it. The fire starts at the bottom, but all of gas soaked stuff, and the match, were at the top.
How to Cook a German Goose by Radar - S1-E24
Revealing mistake: When the boys set the trash can on fire in front of Klink's office, there is a problem with the trash. While the rest of the waste paper burns down there is one piece hanging over the top edge that doesn't burn, even being in the midst of the flames on that side.
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