Continuity mistake: The display behind Klink changes. Sometimes, a map of the area around The Stalag, sometimes a layout of the the Stalag. Also, the picture of Hitler with the microphone bug. Sometimes there, sometimes moved, or gone completely.
Continuity mistake: As Hogan's telling Klink about the drawings, his left arm is extended. The next shot his arm is resting on the cigar box, then back to being extended and notice the pencil under the note pad. Next shot, arm is back on the box and pencil is gone. (00:04:45)
Lady Chitterly's Lover: Part 1 - S6-E4
Continuity mistake: As the boys look at the falling plane, it's light enough to see their shadows. As the guards rush out, it's suddenly dark.
Continuity mistake: After Shultz has been discredited, Klink is taking away the "badges of rank". When Klink goes to crush the monocle Shultz was wearing, he has his monocle on. After the shot cuts to a closeup of Shultz's monocle being crushed, and widens out, you see Klink's monocle is suddenly gone. It remains missing until Klink goes to the hat rack. The shot cuts from Klink, to Hogan and Shultz, then back, and the famous monocle is suddenly back, both without Klink stopping to take it off, or put it back on.
Continuity mistake: Notice the jacket that Carter always wears. It always appears worn with age and use. This episode, it appears almost new.
Continuity mistake: As Schultz is addressing the formation after taking command, his swagger stick switches from his right hand to under his left arm after the camera angle changes. Also, a minute later, Carter goes from being beside Newkirk to being in front of him and back again in a few seconds.
Continuity mistake: After Burkhalter relieves Shultz of command, and Klink is reinstated, Klink sits behind the desk. On the blotter is a letter opener that Burkhalter was toying with, and a black covered notebook. After sitting, Klink reaches in his jacket pocket, pulls out the same notebook, and reads from it. The shot cuts to Shultz and back, and the book Klink read from is gone, (presumably back in the pocket) and the one on the desk is gone.
Continuity mistake: Hogan and Klink are asking Schindler/Brewster about a diversion at the airfield. Brewster has both hands on the coffee cup until the angle change, when his left hand is suddenly out of his pocket.
Continuity mistake: When Klink and Hogan are looking at the Mustangs, Hogan has just sipped his coffee and holding the mug at chest level, at the top button of his coat. When the shot changes, he's holding it waist high. Also, the flight line full of planes is a grainy black-and-white projection super imposed in the shot of the window.
Continuity mistake: Klink's name is still on his office door in one scene but suddenly changes to Privat with no one touching it. (00:18:40 - 00:19:15)
Continuity mistake: When Hogan and Klink are getting ready to take off, they are on a regular paved runway. In the wide shot of the plane, it's going down and taking off from a dirt runway.
Klink for the Defense - S6-E19
Continuity mistake: General Burkhalter is eating Klink's dinner. When finished he places a metal cover over the plate. In the next shot the cover is lying on the table and there is extra food on the plate. (00:15:25)
The Kamikazes Are Coming - S6-E20
Continuity mistake: When Otto and the Russian go to leave there's another man with a blue hat by the door. When the angle changes, there's suddenly a German guard standing behind him.
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