Revealing mistake: During the chariot race, where the contestants are riding towards the screen, tyre tracks from the camera vehicle are clearly visible imprinted in the sand. (00:20:50)
Factual error: Maleficent states that Princess Aurora will prick her finger on a spindle - the part of a spinning wheel that holds the bobbin. Spindles aren't sharp; what Aurora actually pricks her finger on is the distaff, which is used to hold the fiber before it is spun.
Continuity mistake: When Rick Nelson tells Angie Dickinson to throw the plant pot through the window to distract the gunmen who threaten John Wayne he seems to have had a hair cut between scenes as his sideburns are halved by the time he reaches the street and grow again later.
Continuity mistake: It is supposed to be night when Joe slips out of the hotel, but a daytime sky is visible.
Factual error: Iceland sure looks a lot like the California desert.
Other mistake: Mick the orderly is Irish throughout the film, but when Nurse Dawson bumps into him and says, "You clumsy oaf," Mick's reply, "Look who's talking," is said in a London accent.
Revealing mistake: Rock Hudson angrily picks up Doris Day from her bed, blanket and all, and carries her through town to his apartment. When he is walking down the sidewalk, the blanket slips and the supporting wooden board underneath Doris Day is visible. This made carrying her easier.
Continuity mistake: When Molly (Sandra Dee) grabs the letters she had hidden in the suitcase under the bed, her dress is still unzipped in the back. After ranting at her mother for having read the letters, she throws them into the fireplace, only now her dress is completely zipped up.
Continuity mistake: In the opening scenes, the panoramic view of the Larkin homestead shows Lorenzo's "Gummint" Ford sitting with its hood up, days before he has been assigned to the case.
Continuity mistake: The car is out of gas, and Sylva Koscina gets impatient. As the shot changes, Walter Chiari's arm is on top of the car door (it wasn't in the first shot) and Dorian Gray crosses again her arms on top of the bag - assuming the same pose she already had. (00:17:00)