Two Nazis for the Price of One - S3-E17
Visible crew/equipment: A string is seen attached to Colonel Klink's cap that is used to yank off the cap after Colonel Mannheim fires his pistol at Klink.
Two Nazis for the Price of One - S3-E17
Continuity mistake: Freitag is shot at night, but when Hogan goes outside and talks to his men it's daytime.
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. (As another contributor previously posted, the term "nimrod" is slang for a nerdy, doofus type of person, though it's unclear why that was his code name).
raywest