- Creative Differences: Producer Walter Wanger and Alfred Hitchcock clashed repeatedly during shooting. Wanger kept wanting to have the script rewritten with every news story reporting changes in the European situation. Hitchcock, who hated making a movie without the script in absolutely final form before shooting began, pointed out that even if the film were up-to-date at the time of shooting it would be out of date by the time he finished post-production and it was ready for release.
- Harpo Does Something Funny: Robert Benchley was allowed to write his own lines.
- Real Life Writes the Plot: The ending was hastily added when the possibility of the Germans bombing Britain was a very real possibility.
- Unintentional Period Piece: It's quite unlikely that a Nazi conspirator would get anywhere near this sympathetic an ending now.
- What Could Have Been:
- Alfred Hitchcock wanted Gary Cooper for the male lead, but he wasn't interested in doing a thriller. He later admitted that this was a mistake.
- Cary Grant was offered the lead role, but he was busy with Only Angels Have Wings. Clark Gable also passed on it.
- Hitchcock had wanted either Barbara Stanwyck or Joan Fontaine for the female lead.
- Producer Walter Wanger had the story in development for several years. Originally it was about the Spanish Civil War but that war ended too quickly and therefore the story lost its relevance to audiences. Wanger insisted that the film be politically up-to-date so rewrites were happening constantly throughout production. Ultimately, 14 writers in all were involved in bringing the story to the screen.
- Working Title: Personal History and Imposter.
Trivia / Foreign Correspondent