In the rooftop garage scene when Nick runs to his car he passes the windshield of the Ford lying on the ground behind a black car. Immediately after that on the left side after the black car there is an empty parking spot then a gray car, white car and a burgundy car. After he gets in his car backs up and turns around the position of the windshield has moved, the white car is gone and there are now 2 empty parking spots.
When Nick is in the drug store, he buys bandages and a bottle of aspirin. He pops a couple of aspirin and proceeds to re-bandage his hand. Nick is presumably a well-educated man and should know that aspirin is a blood-thinner and should not be taken by someone who is bleeding.
At the end of the parking garage scene, the white bumper of an impacted car is seen resting on the undercarriage of the Ford Taurus. In the next shot, it isn't there. It reappears in the later, evening shot of the same thing, when detective Wallis is surveying the scene.
At the funeral home, Billy pulls $200 in flat bills from Nick's wallet and immediately throws the money (across the room) at the funeral director. The bills that hit the funeral director have been crumpled into balls.
In the rooftop garage scene right before the Ford goes over the rail the shot in the parking lot reveals that the silver van in parked in the parking spot marked 14 - two spots away from the building. However, when the Ford goes over the rail and impacts the van is in the parking spot marked 12 - 4 spots away from the building.
Nick asks the barman where Billy is, he refuses to tell him and Nick bangs his head down on the bar. Then, the man in the seat next to him gets up and Nick hits him. When he hits him, his hat comes off. In the next shot, it's back on his head again.
During the multilevel garage sequence, the camera cranes down to reveal Billy and his gang and then cranes back up again to show Nicolas. When it cranes back up the shadow of a diffusion frame can be seen on the left side of the picture.
In the scene where the police are outside of the house before they kill the mother, the Seal on the police vehicle is for the State of Califorina, but the vehicle is that of the South Carolina Highway Patrol.
Brendan Hume wears a hockey helmet that only has a half visor on it. Though this is used so the actor's face is visible, it is against the rules in minor hockey programs for players to not have a full face mask.
When Nick takes his newly bought guns home and is checking them out and loading them, he spins the open cylinder of his revolver (Colt Python or look alike). A ratcheting noise is heard. The open cylinder of a Colt spins silently.
Several areas of the movie indicate it takes place in California (police car logo, police phone number with 310 area code); however, none of the cars have front license plates which is a state requirement in California.
Toward the end of the shootout in the "Office" chapel, Nick's handgun runs out of ammo and the slide is locked open. He continues to pull the trigger and the gun makes 2 clicking sounds. In reality, once a semi-automatic handgun is empty and the slide is locked open, the trigger is no longer cocked and cannot be pulled.
During the hockey game, Brendan is seen wearing a half-shield visor. In high school, collegiate, and junior level hockey leagues, it is a common rule that full face masks are required for all players. It is not until professional level hockey that players are allowed to wear half-shields or no facial protection at all.
In the rooftop garage sequence, when the Ford is seen rolling backwards (in theory on it's own steam in neutral since the engine's off) alternating cuts/shots show the reverse lights clearly engaged and then not engaged.
On 00:52:00 when Nick finish phone conversation with his wife, he start driving the car and suddenly turns for 180 degrees. Two cars which were coming from opposite direction starting to brake and both of them made a famous movie tire squeal.
Movie was filmed in 2007. and both cars as I know are looking at least made in 2000. or later.
Looks silly that they don't have an ABS system.
On 00:52:25 police photograph is taking a pictures of crime scene on the garage roof.
He is holding about 20 years old analogue (with film) Canon camera.
Unbeliveable isn't it, in 2007. he is using a film camera???
In the bar scene, Billy shows the paper with Nick's and his sons pictures in an article that's obviously devoted to them. The text in the article surrounding their pictures is talking about astronomy and comets.