Revealing mistake: When the Angels are swinging on decoration lights to catch up to Demi Moore in the Shelby, there's no way those lights can swing that far or be strong enough to hold the weight of a person. (01:30:50)
Continuity mistake: When Nat has the record in her hand from all the stuff Dylan left, in the next shot, she is holding a picture of the Angels with both hands, and the record is on the table behind her. (01:06:05)
Continuity mistake: When Bosley holds up the stop sign it is unmarked on both sides, but when Carter drives away there is a large scratch down through the 'O'. (01:10:45)
Visible crew/equipment: When Bosley is a crossing guard and is yelling 'Stop' at the oncoming car, lighting equipment is seen reflected in his glasses. It can also be seen reflected in the cars after the children have crossed. (01:10:40)
Continuity mistake: At the end of the big motorcross scene, the Creepy Thin Man's bike hits a spar right where it connects to a leg on one of the electrical towers. The bike hits above the front tire and flips over the top of the bar, while the obvious dummy falls backward away from the bike. But when it cuts to Creepy Thin Man getting up and staggering off, the bike is back in front of the leg, right behind him. With the trajectory of both falling objects (bike and the Thin Man), he should have been thrown much farther from the metal leg and the bike should have landed yards behind it, rather than the two landing close together. (00:35:20)
Other mistake: In the scene where Bosley is driving the truck into the O'Grady's workyard he is stopped by a man who asks him for I.D. The man says that he has never seen a black Irishman before, but he says this in a Scottish accent. Surely working for an Irish gang he should be Irish?
Revealing mistake: When Natalie is thrown into the rooftop frame by Madison, Cameron Diaz's stunt double is visible.
Answer: It is making fun of the show CSI. Even still, there are ways of telling if someone had a knee problem by the way they walk and put pressure on the foot. Being able to tell if it was a torn tendon, I don't think so. Check out the way people run and you can tell if they have hurt something in the past because of which leg they favor.