Wissenswertes

When the film was previewed in January 1974, John Wayne was being treated for pneumonia in London. He became seriously ill after appearing on the interview show PARKINSON, which had been recorded a few days earlier. The illness was considered life-threatening as Wayne was 66 and only had one lung, and he had COPD in his remaining lung. He began coughing so hard that he damaged a valve in his heart, although this would not be diagnosed until early in 1978.

John Wayne formally separated from his third wife, Pilar Wayne, during filming, although they had not lived together since 1967, and never divorced before Wayne's death in 1979.

Originally intended as a vehicle for Steve McQueen. It was heavily rewritten for John Wayne.

The boat that McQ lives on actually belonged to John Wayne.

John Wayne was 66 (born in 1907) when he played a cop for the first time. Eddie Albert was 67 (born in 1906). Wayne and Albert also costarred in Der längste Tag (1962) together twelve years earlier, where they both portrayed United States Army colonels participating in the World War II D-Day invasion. They were both felt to be too old for their characters in both films.