Continuity mistake: After Bella awakes from the first nightmare, we see her Romeo and Juliet book on the pillow beside her. When Charlie brings in her presents the book is gone, but then reappears on the pillow between shots. (00:03:00)
Continuity mistake: After Tallahassee and Columbus find the yellow vehicle, Tallahassee paints the number "3" on the sides. The style that the "3" is painted in changes throughout the movie.
Continuity mistake: When Romey hits the little boy, she immediately parks her car and gets out. She closes the door behind her and runs to the little boy. After making sure he is ok, she goes back to her car and the door is open.
Continuity mistake: When the kid holds the bible out for Esther in the hallway, in one shot the kid is holding it with one hand, then with 2 when Esther grabs it. (00:32:50)
Continuity mistake: Clay puts a 'Have you seen Whitney' flyer on the back of the SUV. When the car drives past the Crystal Lake sign, it isn't there. When it parks, the flyer has returned and a guy removes it in anger. (00:24:35)
Continuity mistake: The miner wounds Sarah's right forearm during the supermarket chase and the medic bandages it up. Yet, in all subsequent scenes, her arm is fine.
Continuity mistake: When William sees the way forward, he puts his hand on the glass. There is no blood on the glass from the previous shot, and in the next shot, when he tells Addy to be careful, the blood is back. (00:39:20)
Continuity mistake: The private who was being injected with the blood substitute explodes, splattering red goo all over the glass panel. The amount increases in shots from outside the room, covering the entire panel. (00:14:45)
Continuity mistake: When Renée Zellweger drives up in front of her house the first time in the movie, as she shuts her car off, her window is down. When she gets out, the window is back up.
Continuity mistake: When Max is going to stab Naoko at the end of the movie, he grabs her by the hair, but in the next shot he's grabbing her by the chin. (01:18:30)
Continuity mistake: During the car wash scene a pipe is bursting, but then the amount of water changes slightly in the next couple of shots.
Continuity mistake: After Megan dies, for real, Jessica tells the others that they loved Megan and Megan loved them. Her robe opens and closes between alternate shots.