Continuity mistake: After Barry has jumped into the water reclaim the crown, he comes out of the water with a perfectly clean shirt, but in the next shot the blood is back on his shirt as expected. (00:22:50)
Continuity mistake: Max lies dead in Julie's car covered in crabs. He was hooked very deep under his chin, yet when we see him, the wound is gone. (00:59:15)
Continuity mistake: When Helen finds the word 'SOON' written on her mirror she smashes it. There are two shots of the mirror being broken - in the first the center of the cracks is between the O's and in the second it is in the middle of the first O. (00:57:50)
Continuity mistake: When Julie comes home and finds the letter, her lips are pale and she is not wearing lipstick. When the shot shifts focus from the letter to her face again, however, she is wearing purplish lipstick.
Continuity mistake: When the Fisherman jumps out at the girl in the store when he is in the plastic bag, he misses and falls to the floor. If you look at the Fisherman when he is on the floor and waving his arms notice he isn't carrying his hook. However, in the next shot when he is standing up, the hook is in his hand again.
Continuity mistake: Ray falls off Ben's boat towards the end. Yet when he gets back on board he's dry.
Continuity mistake: When Julie gets on Ben's boat, she sees a picture of Helen at the parade from that day. This implies Ben took a picture at the parade, got it developed, then went back and killed Barry and Helen. There's no way.
Continuity mistake: When Helen sees in the mirror that her hair has been cut, she's holding her head with one hand but in the close-up she's holding her head with both hands. (00:57:52)
Continuity mistake: In the iconic scene where Julie screams "what are you waiting for?", she at first faces Barry and Helen then she turns around. In the next shot, she's still facing them and has to turn around again. (01:00:44)
Continuity mistake: When Barry tells Ray to go check if the fisherman is alive, Barry's flashlight keeps changing position from his right hand to his left hand. (00:15:58)
Continuity mistake: When Ben gets run over his body is shown hitting the windshield but when they find his body it's shown that his face took all the damage.