Continuity: Mosely's arm on the back of his seat after Jack is put in the car.
Continuity: The hand that Jack's cigarette is in when he is about to let the Duke out of the bathroom on the train.
Continuity: When Tony Darvo gives Jack his phone number, he can clearly be seen writing it on a matchbook cover in pencil. Yet when Jack refers to it later, the writing is in blue ink.
Continuity: Mardukas' handcuffs changes hands when he is in the river.
Revealing mistakes: Mardukas has three shadows when rescuing Jack from the river.
Continuity: Walsh's cigarette changes hands when he's talking to Moscone on the phone from the airport.
Continuity: After Jonathan hands him the money belt, Walsh unzips it twice.
Continuity: In boxcar scene, Jack is smoking in one angle, not in the second.
Continuity: Just after leaving his ex-wife's house, Jack makes a collect call to Eddie Moscone. Jerry answers the phone and Jack immediately starts talking and telling him to put Eddie on the line. No one actually accepted the collect call.
Errors in geography: The action in the movie takes them through Amarillo, Texas, in the Texas Panhandle. Mountains can be seen through the buildings in the background. The geography of the panhandle is a flat, treeless plain.
Continuity: When Walsh tussles with Mosley and his men for the first time outside the police station, the same woman in the dark shirt with spots walks by the group at least three times.
Continuity: A clock in the background LA airport shows the time as 12:30. Shortly after, we hear that it's 11:35.
Factual errors: When we see Alonzo Mosley in his office he has a California State Flag. However, since he is an FBI agent he would not have the state flag in his office.
Audio/visual unsynchronized: When Dorfler takes the duke to the airfield after taking him away from Jack, the duke tells him that he can't fly. Dorfler tells him to sleep on it and knocks him out with a punch. The sound of the punch is noticeably out of synch with the punch.
Continuity: When Dorfler is driving in his car, the cloud pattern in the sky behind him changes from cloudy to clear and back again.
Factual errors: In the penultimate scene in the film, Mardukas gives Jack a money belt full of $1,000 bills. He claims he kept it as "some traveling money." However, U.S. Government has not produced $1000 bills since 1945.
Revealing mistakes: When Moscone returns to his office from Chen Lu's after Walsh tells him his phone is tapped, he catches the sleeve of his shirt coming through the door, tearing the cuff open. Joe Pantoliano realizes it, but continues delivering his lines.
Continuity: When meeting with Jimmy after the botched capture of the Duke neither thug has a bruise on his face. Marvin pistol whipped both of them.
Errors made by characters (possibly deliberate errors by the filmmakers): Jonathan "The Duke" Mardukas is an accountant who has trouble counting. While singing "100 Bottles of Beer on the Wall," he skips from 96 bottles directly to 93.