Continuity mistake: When Jack first arrives in his office at the bank after his family has been kidnapped, as he is sitting down, the phone on the table in front of him is sitting at an 8 o'clock position. Next shot shows the phone sitting at a 6 - 7 o'clock position. (00:26:50)
Revealing mistake: In chapter 14, Bill Cox calls Harry, who's asleep in bed. Harry answers his flip phone, but doesn't flip it open. (00:54:50)
Factual error: When Janet dials 911 from her cell phone, we hear a low tone followed by two higher tones. In reality, 911 is a high tone followed by two lower tones. Additionally, she dials 911 and puts the phone up to her ear without ever pressing the "Talk" button. (01:35:10)
Factual error: Text doesn't actually move up a screen, it only appears to; it's really only blinking lights. As such, the improvised scanner wouldn't work, you'd only get a small slice of each line.
Other mistake: In the scene where Mary Lynn Rajskub is driving Harrison Ford around, she is told at the beginning of the scene to "pop the clutch", signifying that she is driving a manual transmission vehicle. However, during the drive, she never removes her hands from the steering wheel to shift gears.
Audio problem: When Jack is in the server room (about half way in the movie) it's pretty quiet. Normally that many servers make a lot of noise, not to mention the air conditioning. But there they are, talking with no background noise whatsoever.
Factual error: During Jack's drive to work in the "morning", the sun is shining on Seattle from the west.
Continuity mistake: The 70s vintage green Plymouth belonging to the secretary, has what appears to be an inspection sticker on the driver's side of the windshield. However, when the vehicle catches fire near the end of the movie the sticker is missing.
Deliberate mistake: When Harrison Ford and Mary Lynn Rajskub are crossing the tracks, its Rajskub who's driving the car, not Ford. This is because the filmmakers originally had Rajskub driving the entire way. They later refilmed the drive with Ford driving, but kept the shot of them crossing the tracks the same. Ford and director Richard Loncraine confirm this on the special features of the DVD.
Factual error: This film depicts wire transfers as happening instantly. Electronic transfers of funds actually take 2 business days - 3 if the transfer is submitted after the Federal Reserve has closed for the day.
Continuity mistake: In the scene were Jack is getting ready to fight, he tells the family to run. Notice how their handcuffs are still on. Later on, Jack goes to the family, and somehow someone had a key.
Continuity mistake: The pickaxe handle that Jack reaches for when he and Cox are fighting in the grave changes position and then back to its original position in quick cuts before he grabs it. Look very closely.
Plot hole: At the beginning, Bill or his henchman are seen watching the family in the house, which they would have course be doing always. If that is so, then why do they not know about the toy car remote that screws up the video signal in the house?
Continuity mistake: When Jack shows Cox around the server room the first time, he shows him that there are no longer any service terminals, for him to run the program Cox has brought along. Whereas when they bring in the home-made scanner, there's suddenly a terminal for them to use. Why couldn't that terminal have been used the first time?
Continuity mistake: When Jack pulls over the railroad tracks in the green Dodge, the headlights are missing. Just a few minutes later Jack is driving over the wooden bridge with headlights right where they should be.
