Continuity mistake: In one scene after Hutch is beaten up on the bus, he has no facial injuries. Then in the next scene, they are back.
Other mistake: During Hutch's flashback to when he was about to assassinate the man who skimmed $1 million, he says he was holding an H&K .45. However, at that exact moment you can see "9mm" on the side of the gun.
Revealing mistake: When making traps, he's harvesting powder from a spent shell (primer has been struck). (01:05:50)
Continuity mistake: RZA is first seen using a bolt action rifle in a left-handed configuration but in later shots the rifle is right-handed. Not sure if they mirrored the image in the close up because they couldn't get the right camera angle or if they were genuinely trying to make his character appear left-handed. (01:16:02 - 01:17:49)
Deliberate mistake: Hutch is in the trunk of a BMW 7 series ranging in years from 2001-2008. The trunk is equipped with an interior trunk release cable if somebody gets trapped in the trunk. While the car is in motion Hutch manages to free himself of his handcuffs and open the trunk. If the trunk is opened while the vehicle is on a light would flash on the drivers display alerting him/her to "trunk ajar" with a little picture of a car with an open trunk. I know I had one for 5 years. (00:51:50)
Other mistake: While being shot at in the Challenger, you can see most of the rounds impact on the driver side door but more importantly the bulk land where they would be hitting Hutch without a doubt, and car doors aren't bulletproof. (01:15:01)
Character mistake: When the neighbor is showing off his Challenger he states it is a 1972 4.9 liter. Dodge never made a 4.9L that year, only a 3.7L, 5.2L and 5.6L.
Continuity mistake: When the Russians drive up to the house, they are in a van and 2 sedans. They leave in the sedan that he crashes. When they leave, the van is gone. (00:48:14 - 00:50:47)
Audio problem: When Hutch re-enters the bus, Teddy tries to pull a gun on him. Hutch snatches up a bus grip (a pole made of lightweight, plastic-coated aluminum) and bashes Teddy into submission with it. After Teddy goes down, Hutch tosses the aluminum pole to the rubber-lined floor of the bus, but the sound it makes is that of a heavy iron pipe falling on concrete. Bad sound effects.
Factual error: The film begins and ends with Hutch handcuffed in custody, being interrogated by two police detectives. He was apprehended at the scene of a major violent crime with many fatalities, he has a gunshot wound, and he's a likely murder suspect. In real life, Hutch would be strip searched and treated for injuries under tight security, and he would not be allowed to carry personal effects into the subsequent interrogation. But during the interrogation, Hutch impossibly produces a pack of cigarettes and lighter, a can of cat food, a metal can opener and a live kitten from inside his jacket.