* AbilityOverAppearance: The character 'Gillie' was meant to be a boy, but changed to a girl to accommodate Hayley Mills.
* FakeNationality: Polish Bronek is portrayed by German actor Creator/HorstBuchholz, and the Colombian crew at the end of the film are played by Cypriots.
* RealLifeRelative: Creator/JohnMills and his daughter Creator/HayleyMills both starred in this, he playing a police detective and she the lone witness to a murder he is investigating.
* ThrowItIn: A scene where Gillie tells the police about the murder was mostly ad-libbed. Hayley Mills was given the basic plot for the scene and told to make her own dialogue up.
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