Continuity: When John and Larita drive to the ruined castle and get out of the car, they leave the car doors open. After a head-shot of the two talking to each other, they walk past the car towards the castle, and the driver's door is now closed.
Revealing mistakes: When Larita first sees John after the race in Monte Carlo the mechanic in the bottom right of the shot takes his hat off and waves it in the air. A second or so later when she looks back at John, the same mechanic takes his hat off and waves it again indicating the shot was duplicated.
Anachronisms: Both Larita and Marion are seen reading "Lady Chatterley's Lover," which was not published in England until 1960 (the film is set in the late 1920s or early 1930s). (Of course, Larita could have brought the book with her from the Continent.)
Anachronisms: While in the nursery, John refers to something not scoring Larita any "brownie points." This phrase did not originate until the 1960s.