Continuity mistake: When Robert Wagner falls, halfway up the mountain, Spencer Tracy's rope, which is attached to Wagner, runs through his hands, making them bleed, but, finally, he gets a grip and he pulls Wagner up. As we see Tracy's rope, as it slowly comes up, but there is no blood on it.
Continuity mistake: Milly is on the balcony with Mr. Hanson. The sliding glass doors behind them are not fully open and the drapes are drawn well past the door opening. When Mr. Hanson stands up, the camera cuts for a closer shot and the sliding glass door is now fully open and the drape is drawn to the door opening. (00:56:00)
Continuity mistake: When the bulldozer is pushing the boat on the beach, the driver is initially dark skinned with a hat. Then next shot he is fair with no hat. Then back to dark skinned with no hat. (00:24:55)
Continuity mistake: After his meeting with Julia, Winston at home opens the drawer and in a close-up pulls the diary out from under a stack of papers which he lifted with his left hand. The angle changes, and his left hand is on the edge of the drawer, and not supporting the papers any more, nor any paper is visible. There's also a pen on the table that should have been visible before, but wasn't there. (00:36:25)
Character mistake: Aunt Monica wants to give a pendant to Rhoda that has a garnet in it. She says that it would need to be replaced by a turquoise, since that's Rhoda's birthstone. No month has turquoise as its birthstone. (00:06:04)
Continuity mistake: Marquise Maria de Crevecoeur is in her room when Monsieur Duval knocks at the door. Her veiled hat is by her on the sofa. A minute passes; nobody touches the hat or comes close to it, but when Marlene Dietrich gets seated again, the hat and its long veil move. (00:16:50 - 00:18:00)