If it's a true story, why...?
According to Wikipedia: "The film is based on a true story of an innocent man charged for a crime he did not commit. The story was based on the book The True Story of Christopher Emmanuel Balestrero by Maxwell Anderson and the article "A Case of Identity" (Life magazine, June 29, 1953) by Herbert Brean. It was one of the few Hitchcock films based on a true story, and unusually for Hitchcock, the facts of the story were not changed much". Indeed, Hitchcock says more or less the same thing in his introductory cameo.
Why, therefore, do we read that "The story, all names, characters and incidents portrayed in this production are ficticious. No identification with actual persons, living or dead is intended or should be inferred"?
Can anyone explain?
Thanks