Revealing mistake: Near the end of the film, when people are running in terror out of the theater and into Times Square, you can see that the people are not leaving any footprints in the snow. The snow must have been digitally added to the scene.
Revealing mistake: In the scene where Jane is trying to run over John with her car, she jumps from the driver's seat while John is in the back of the car. Right before the car crashes through the fence, you see John through the back window. You also see a head in the driver's seat, even though no one is supposed to be driving the car.
Revealing mistake: When Chris and Jamie are on their day date in the diner, Jamie has a grilled cheese sandwich with ranch on the side. However it is obvious that the bowl of ranch is empty. (00:33:10)
Revealing mistake: When Herbie is being pulled from the truck at Crazy Dave's, Herbie goes into reverse and the camera does a closeup shot of one of the rear wheels reversing. If you look carefully, you can see an extra set of small wheels behind the tyre which are obviously propping the car up enough so that the cars proper wheels will only skid and not get any traction.
Revealing mistake: On many occasions throughout the film, Keira Knightley's real, short hair can be seen under her wig.
Revealing mistake: Very obvious stunt double when Dennis Quaid's character falls off the forklift into the kiddie pool at the hardware store.
Revealing mistake: In the shot when Rosario cries in silence with her dead brother at the bed he moves the little finger of his left hand.
Revealing mistake: When Rose and her boyfriend are making a toast in her apartment we hear a perfect chiming sound. We can see that they're both holding their glasses by the bowl instead of holding them from the stem. Holding a glass this way would never allow a chiming sound.
Revealing mistake: In the scene where Hitch first meets Albert, Albert spills his soda. The can shoots open and spills over the steps. If you look closely the label on the can is upside down. This would be fine if the coke was spilling out of it but it shoots out and when he picks it back up it is still upside down.
Revealing mistake: When Adam jumps from the hay bale in the dance hall and the men catch and flip him, his stunt double is very obvious, his hair is darker than Adam's hair.
Revealing mistake: During the song "Remains of the Day", at one point, towards the end of the song, you can see metal wires in Bone-Jangle's wrists, revealing how the stop-motion character was kept together.
Revealing mistake: The movie is set to take place in Connecticut, however, a train passing by is a New Jersey Transit train showing that it was, in fact, filmed in New Jersey.
Revealing mistake: When Tessa plays a QuickTime movie, the movie's counter stays at 0:00 and the progress indicator doesn't move.
Revealing mistake: At the clinic, when Sushmita Sen reads Katrina Kaif's suicide e-mail, she is reading it in a Yahoo "Compose" e-mail window, which means the note was typed on the clinic computer, not Katrina's computer. (00:10:20)
Revealing mistake: When Jack and Ennis are cliff diving naked, if you look closely at Jack when they both run and jump off the cliff you'll see that it's not Jake Gyllenhaal but rather his stunt double.
Revealing mistake: When Andy flies through the billboard from his bicycle, there is no driver in the truck the advertisement was on. You can see through the side window and mirror that no one is in the truck.
Revealing mistake: When Abbey grabs the knife and threatens David, David falls and hits the tea party table, sending the tea set onto the floor. As Elizabeth crosses to be next to David, her foot hits a pink tea cup piece on the floor sending it rolling away behind her. As a ghost her foot should have just passed through the object. (01:06:45)
Revealing mistake: During the fight in the apartment, the girl in the shower is wearing a black thong. (01:44:00)