The Battle of Stalag 13 - S2-E5
Revealing mistake: When the scene transitions from Klink and Hogan to a night shot outside of the barracks, you can see palm trees above the roof line. Not normal for the area that's supposed to be represented.
The Battle of Stalag 13 - S2-E5
Visible crew/equipment: As first Feldkamp, then von Kattenhorn, get in their respective staff cars, the camera crew and equipment is reflected on the doors and glass.
The Battle of Stalag 13 - S2-E5
Continuity mistake: Newkirk and Le Beau are getting the girl into the tunnel via the doghouse, while Hogan has Schultz distracted. Look over Schultz's left shoulder. The doghouse is in its correct position, as you can see the roof. When Schultz turns around, Le Beau and the girl are pulling the doghouse down, where it was down about one second earlier.
The Battle of Stalag 13 - S2-E5
Continuity mistake: At the end, as the staff car leaves, the guard has the gate open. You see it's a single gate, suggesting the fence is a single, whereas in other episodes, you see two sets of wire. The gates are double, with a bar on the top to open both gates (inside and outside) at once.
The Battle of Stalag 13 - S2-E5
Continuity mistake: As Hogan leaves Klink to go to his barracks, there is a distinct lighting difference on the porch where Klink is. The area between the supports of the porch roof is lighter in color than to Klink's left, also the shadows of the trusses are at a different slant than the area to the right of the screen. And there are extra shadows of the light and the support to Klink's left.
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