Revealing mistake: When Yoichi's mother is killed, the blood coming from her body is very obviously just colored water, as it is too bright and too thin to really look like blood.
Continuity mistake: In the scene when Nick Chen (Chow Yun-Fat) talks to Jack (Jon Kit Lee) at the NYC Correction, the shot facing Nick shows him grabing Jack's face by the chin. The next shot, facing Jack, shows Nick's hand around Jack's neck. The final shot facing Nick again shows his hand back on the chin. (00:58:50)
Continuity mistake: In the scene where Amelia is driving the truck full of policemen to the scene of the second (Mrs. Rubin) murder, the shot changes a couple of times before it settles looking through the front windscreen at Amelia. Through the rear windscreen of the truck, you can clearly see the highway and all the cars on it behind them. Amelia turns the steering wheel sharply to the left, and you hear the screeching rubber-tyres-on-tarmac noise as if she really had swerved left, but the scene of the highway behind them seen through the rear screen does not alter at all - as if she was just going in a straight line all the way.
Continuity mistake: When Maggie talks to Eddie Bo Smith Jr. (the Chicago cop) outside the meeting of "receivers", you can see the cop's breath when he speaks, but not Maggie's.
Continuity mistake: After Hall has been shot in the leg in the simulation of LA 1937 the hole in his trousers and his injury disappear, as seen in the fight sequence at the pool. Hall even uses his leg to hit the bartender in the stomach, what would have made this very painful if he had been shot there.
Factual error: The story takes place in the Pacific Northwest (Vancouver) in November and December. Washington may be known as the "Evergreen State", but there are still numerous deciduous trees - and deciduous trees have leaves that change color in Autumn (yellow, orange, red) and then shed (fall off), not stay green through December or into the new year.
Visible crew/equipment: When the housekeeper says goodbye to Shigeharu you can see the boom microphone on the right side of the screen. Next to the light hanging above the dinner table. (00:16:42)