Factual error: Burkhalter refers to Jesse Owens winning the gold medals in the Berlin Olympics, and that Hitler left the stadium every time Owens was to be presented a medal. Truth was, Hitler left the stadium when another black man won the day before, and didn't snub Owens at all. In fact, Hitler wasn't in attendance the days Owens won.
Continuity mistake: Klink comes out with the "insurance policies" in his hand. They are lying beside each other, with a little space between them, and tilted in one position in his hand. When the camera goes into a close up, they are touching, and in a different position.
Revealing mistake: As the building is being prepared for the upcoming event, and men are going in and out, as Shultz goes to report to Klink, look past him and the roof behind him. You can see the studio water tower in the distance.
Other mistake: Usually, the picture at the podium has the microphone "bug" for Hogan, and it's blatantly obvious, except to the Germans. This time, there is no bug, but an extra picture that the boys can take the eyes out of and listen in.
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