Continuity mistake: After the flower market scene. Mr. Houston and Cary Grant are at his hillside villa drinking wine outside the porch area. Cary tells Houston to bring the wine. Houston does not pick up the bottle. As they are walking to the table you can briefly see the table and there is no ice bucket beside the table. When the camera changes there is now an ice bucket beside the table with the bottle of wine in it. (00:27:10 - 00:27:45)
Continuity mistake: When Grace Kelly says goodnight to Cary Grant and kisses him, she is not tanned. The next morning when they meet again, to go for a swim, she has a sun tan worthy of several weeks worth of sun bathing on the French Riviera. (Or it's bad colour correction on the print). (00:40:00)
Continuity mistake: When Cary Grant and the insurance agent are walking through the flower market, the girl in the bright pink dress walks past them twice.
Continuity mistake: A short time after Cary Grant changes out of his clothes and says he is leaving with the boat girl, he is seen with the previous clothes on again.
Continuity mistake: Keep an eye on the letter that Cary Grant has with all of the names of the potential theft victims. 1) The way it is folded changes from 3 folds to 2 and from up to sideways. 2) The suite numbers are wrong , as seen when CG goes to Grace Kelly's, and it is different from the list.
Continuity mistake: When Cary Grant swims to the floating dock to speak with Danielle, the ladder attached to the dock is not covering the L in hotel in a couple of shots.
Continuity mistake: In the hotel bedroom, during the fireworks night, when Grace Kelly calls Cary Grant, "Robbie," his arm is bent towards his chest, but in the immediate wide shot it's straight and he then bends it.
Character mistake: Early in the movie Cary Grant is on the beach and is told he has a phone call. While conversing with Bertani, Cary Grant has the handset backwards - he is speaking into the earpiece and listening to the mouthpiece where the chord is attached.
Continuity mistake: Robie is wearing a kerchief around his neck. The knot on the kerchief keeps moving.
Continuity mistake: When Cary Grant is on the speedboat, he is wearing a red polka-dot scarf at his neck. The position of the scarf changes from shot to shot, as evidenced by the dots rearranging themselves.
Continuity mistake: Just before Danielle swims to the swim platform she is wearing red nail polish. Once she climbs onto the platform she has none on.
Continuity mistake: When leaving the beach after Robie closes the insurance note he looks at the young man doing pull-ups. On the green table behind the young man are two papers/magazines, but after Robie hands the young man the key they're not.
Continuity mistake: After swimming when Robie walks up to Frances at the Carlton Hotel there is a car with no luggage on the roof stopped behind her in the Hotel driveway. When the camera changes the car also changes. It is now just pulling in with luggage on the roof.
Continuity mistake: When Robie returns to the Carlton Hotel after swimming, he is passed on the street by two women on his left going to the beach - one is wearing a white/blue/green dress. While Robie and Frances talk on the steps of the Carlton the same two women are now on the other side of them by the Hotel, walking down the Carlton Hotel driveway.
Revealing mistake: Foussard is killed and his body dropped off the cliff into the sea. There is a close-up shot of his head and torso, facing upward, that is supposed to be underwater. However, the actor is obviously not in water. His hair, that should be floating loosely around his head never moves and appears to be held in an outward position by stiff hair gel. Some type of "special effect" filter is layered over the entire shot to simulate water rippling over the corpse.
Continuity mistake: Danielle is lying on the float then goes to sit up. The first lower camera shot shows her left leg bending behind her other knee. The high camera angle change shows both of her legs fully extended.
Continuity mistake: When Cary walks into the office at the restaurant of his friend there is a clipboard hanging on the wall of glass. It disappears near the last scene in the office. No one leaves with it.
Continuity mistake: At the restaurant of his friend, while in the kitchen the waiter with the silver streak in his hair sets down two bottles of wine on the coffee table and turns his body away from them. The labels are facing the office. Moments later when Cary picks up one of the bottles the label is facing into the kitchen. The bottle only has one label, as shown when it is thrown to the dishwasher and he catches it then turns the bottle.
Continuity mistake: When Cary walks into the office at the restaurant of his friend there is a brown wooden box on the desk near the lamp. When the restaurant owner comes into the office the box is silver and then changes back to a brown wooden box in the next shot.
Revealing mistake: When Cary walks into the office of the restaurant of his friend, the egg is thrown from Cary's left yet the camera/Cary only looks at the people to his right in the kitchen.
