How to Win Friends and Influence Nazis - S3-E7
Continuity mistake: In the long shot of the hotel room, the boys are lulling Schultz to get him to sleep. In the long shot, his right hand is holding the rifle. In the close up, it's barely draped over the rifle.
LeBeau and the Little Old Lady - S3-E25
Continuity mistake: When Newkirk and Carter are playing Gin, Newkirk puts a card on his forehead so Carter can't get it. When he puts it on his head, it's about a quarter inch below his hairline. In the close up, the card is now at the hairline. In the wide shot, the card is again about a quarter inch lower.
What Time Does the Balloon Go Up? - S3-E24
Continuity mistake: When the British spy is trying to get to the camp, the area around him seems fairly lit, as at dusk, after the sun just set. When he glances toward the gates, the sky is black, suggesting night (the shot of the gate is stock footage). When the shot goes back to the spy, it's dusk again.
Continuity mistake: When Klink goes to leave his quarters to meet the plane, he doesn't have his familiar outer coat in his arm or on him. When he gets to the rendezvous point, he has it on.
Axis Annie - S3-E23
Continuity mistake: At dinner in the hotel, Hogan suggests a picture. Axis Annie agrees, and reaches down for the camera. After the shot cuts to a wide angle, she is reaching down again.
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