"Stern" magazine, which was releasing the fake Hitler diaries in real life, released a podcast in 2019, in which they were also discussing the movie. There they mentioned that the story is very close to the real events and very little was invented, with the exception for the character's names. Former editor in chief Michael Seufert told then that director Helmut Dietl was asked, why various absurdities from the real story were not included in the movie. He said that some of the real events were so absurd that the viewers would take it as too crazy and would be angry about Dietl.
Mario Adorf wanted to play in this movie, preferably the role of Hermann Willié, which went to Götz George, or the role of Fritz Knobel, which went to Uwe Ochsenknecht. Adorf later admitted that he had been offended for a few years, that Helmut Dietl didn't cast him in any role.
The character Freya von Hepp, who is portrayed as the niece of Hermann Göring in the movie, is based on Edda Göring, who was in real life the daughter of Hermann Göring. For 5 years she was also friends with the journalist Gerd Heidemann, on whom the character Hermann Willié is based on.
While in the end of the movie Hermann Willié on his yacht was followed by the police on the Elbe river, in the earlier alternative version of the movie the captain of a port police entered the yacht. This police officer was played by Gerd Heidemann himself, the real-life reporter of "Stern" magazine who investigated the Hitler diaries and upon whom the character Hermann Willié is based. However the version with this scene was not showed yet. Heidemann also played a waiter in an earlier scene, but this scene was deleted from the final film version.