In the bathroom of The Boiler Room, Trevor knocks down the right soap dispenser. However, in the next shot it is up again.
In the driving sequence after Trevor is asked if he has had any head injuries, the cigarette lighter position changes between the time it is pushed from when it pops out.
Scene at 00:25:33 and scene at 01:05:38 are the same footage.
When Reznik pulls up in his truck outside Miller's house he parks a couple of feet from the curb, when he returns the truck is tight against the curb.
When Trevor is telling Stevie that he hasn't slept in a year, Stevie says, "Don't worry about it, Honey, everyone gets insomnia now and again" and he explains that he's had it for a year, Stevies nipples alternate between flaccid and hard between shots. (you know you wanted to post this one).
When Miller gets caught in the machine, it clearly shows his fore arm amputated. During Reznik's questioning, they show detached fingers, not an arm. Confirmed later by Trevor.
When Trevor is fleeing Miller's house, trying to keep up with Ivan, one intersection has both a RYG traffic light and a stop sign.
The energy bill that Reznik opens, 20 minutes into the film, shows the unlikely meter number of "123-456789". Presumably it was hoped this would not be spotted with the distraction of the large FINAL NOTICE above it.
The same RV that is in front of Miller's house, is used in another scene, where Trevor is exiting the tunnel, and nearly hits an RV. It is the same RV.
Around the 1:08 time mark, you can see a parked car (Mazda) with the license plate NNW 882. The car that hits Reznik a couple of seconds later is a Volks Wagon with the same license plate.
(at around 55 mins) Trevor flips the light switch a couple of times. The last time he does so, he flips it down, even though it is already down. However, an added clicking sound can be heard.
While sitting in his truck at the airport terminal car park (1hr 19 mins) the feet of the cameraman can be seen briefly in the truck's metallic wing mirror.
Trevor can be seen washing himself above a bathroom sink branded "Roca". This brand of Spanish origin is not distributed in the United States, where the movie is supposed to take place.
Though the film is set in California, the pavement markings in the streets are European, e.g. no center yellow stripes.
The STOP sign around 30m 45s into the movie as Trevor pulls out of the factory is not a standard STOP sign. The letters are too small.
When Trevor is digging for the picture of Ivan in his wallet at work and yelling at his coworker, Christian Bale's native accent can be heard.
When playing "Hangman," a part of the body is drawn only after a wrong letter has been guessed; in the movie, Trevor draws a body part before filling in a letter.
Trevor sees the license plate of Ivan's car and says to himself "743 CRN," but the actual plate in the shot shows CRN 743.