Continuity mistake: When Michael and Shorty are having lunch after Michael is released, he empties the contents of the envelope onto the table. A bit later he puts everything back into the envelope, but the bullet remains on the table under a napkin. Later in the movie, Michael empties the envelope and the bullet is in it.
Continuity mistake: In the scene where the police car is chasing Ben Affleck and Uma Thurman on a bike down in a tunnel, in one shot, the police car's flashing light on top is ripped off by the low ceiling. In the very next shot, the lights are still on the top. The next shot shows the lights are gone.
Continuity mistake: When Rachel takes the 'Photo Album' out of the bag and places on the bed, she places it between the bag and a white towel. However when the shot changes to show the bed again which Michael then sits on, the 'Photo Album' is sitting partially on the bag and the towel has moved. There is also other clothing on the bed that wasn't there previously.
Continuity mistake: In the scene where Ben Affleck is walking toward a stuffed animal stand, you see a small red dog facing toward the camera. In the next side shot, when Ben is picking up the parrot, you see the same dog still facing toward the camera when you should see the dog's side.
Continuity mistake: During the scene in the apartment after the car chase, Uma has just had a shower, and she begins to empty the bag she brought. When she reaches in to pull out his clothes, there is a silver photo album on the bed. When the shot cuts back to the bag, the album isn't there, but she pulls it out of the bag AFTER the clothes.
Continuity mistake: After the real Rachel has knocked out the fake Rachel, Mike looks over her shoulder and sees Colm Feores' character sighting a gun on her. He pulls her to the side and, in doing so, knocks over two wine glasses that were on the table. Then the shot switches to show the view from the window and the wine gasses have disappeared. A moment later as Mike and Rachel fall to the floor, they're back.
Factual error: In the scene where Michael is patching the ATX motherboard with a paper clip, the sparks coming out of the box are ridiculously long for being low voltage flashovers, especially as the motherboard has no power supply connected to it. Even if the board would run directly on mains voltage the flashovers would only be a couple of millimeters. Furthermore, flashovers are blue, not yellow as shown.
Continuity mistake: When Michael Jennings first realizes that the stamps on his envelope are one of the items and he looks at the faces on the stamps through the magnifying glass lens, you see one of the eyes consisting of 9 black squares with each square being a newspaper. In the next scene, with Michael and Rachel at the school, the eye is now a round black eye with 6 white squares, with the first five being newspapers and the last being a picture of the time device screen.
Continuity mistake: When Michael and Shorty are having lunch, Michael watches the lottery numbers on the TV. He confirms the numbers on his fortune tag that has the phrase on the back, "If you only look where you cannot go, you will miss the riches below". The shot goes back to the TV, and then back to the fortune paper. If you look through the paper to the phrase on the back, it says something about a "wise man". Obviously a different piece of paper.
Revealing mistake: In one of the shots of a newspaper you see a serious grammatical error for a headline. The use of "it's" instead of "its". It was something to the effect of "Ahead of it's Time". Forgivable for a note left by a character, but a mistake that real newspapers just don't make. Just FYI: The actual headline is "Nexim Announces It's Answer to ARC's Living Display".
Continuity mistake: When Mike goes to meet the fake "Rachel" at the restaurant, note the yellow flowers on her table. They are centered, but against the edge of the table (where a person opposite her would sit). The next shot of Jimmy's screen shows they've moved to the far right (as seen from the fake's perspective). When Mike opens the envelope, they've disappeared completely and, a moment later, they're back (with some of the leaves curled around the stem of a wine glass).
Continuity mistake: As the truck is approaching the car from Allcom, the view is from the interior of the car (front window, the vertical panel between the windows, rear window) and the semi is right on top of the car. It switches to a wide shot and now the truck is considerably farther back.
Continuity mistake: When Jimmy visits Rachel in her apartment to tell her that Michael has left, in the shot from over his shoulder he places his right hand on her shoulder and then moves it down to the top of the arm and starts 'massaging it'. However when the shot shifts to in front of him his right hand is just sitting on her shoulder. It changes back again when the shot changes.
Other mistake: Several times, Jennings sees himself being shot on the catwalk, and each time there is a closeup on the flying bullet as it travels toward his chest. But in the following shots, as he falls to the ground, there is never any indication of a wound where the bullet should have hit. The time viewer is always perfectly accurate and bases its predictions on the determined actions of the present, not theories of what actions could take place in the future. There is no way the time viewer could simply be omitting this detail.
Factual error: In the scene where Mike is in the subway trying to short the controls with a paperclip; the circuit board appears to be an ATX computer motherboard. The cards he pulls out appear to be PCI cards. Also, the motherboard is missing RAM and has no power supply attached to it. Furthermore, why would sensitive electrical circuit boards be mounted in a locked metal box in a damp subway?
Factual error: When Ben finally uses the machine, we see a lot of flashes of events, some from the recent past (the items he sent himself), and some from the future (war). However, one shot of a future nuclear blast is actually a famous picture of a specific explosion from the '60s, I think (an above ground test on an island somewhere), just with a city superimposed at the front of the photo instead of some watery flat land. I've got a poster of that very explosion on my wall. Hardly a future event.
Continuity mistake: After Ben Affleck finds the bug in the machine, he pulls the bit out and turns to Uma Thurman. In that shot of Uma we see that Ben's got a big smile on his face. It then cuts immediately back to just Ben, who has a straight face and immediately cracks a big grin.
Continuity mistake: In the final fight in the greenhouse, towards the end, Michael picks up a Glock 17 off a dead or incapacitated guard. In the next scene that he emerges with the pistol, the scene involving the standoff between Michael and Rethrick, it has suddenly changed to a Browning BDM.