In the director's cut, when Kenny and Gary have stolen the guns and the old man shoots a hole in Gary's hair, Dean says, "are you all right, Gary?" His lips ask "Gary?" again, but is only heard in the next shot of the smoking hair. The original region 1 version has the sound in sync with the lip movement.
It was said that Eddie had a gift of reading the slightest reaction in an opponent in a game of poker, yet, when Harry makes a very noticeable reaction with his eyes, Eddie continues to bet a huge sum in the face of imminent loss.
When Dog describes Golf as a "way to spoil a good walk" he attributes the quote to Winston Churchill. The quote "to play golf is to spoil an otherwise enjoyable walk" first appeared in 1903 in a book by H. S. Scrivener.
During the closing sequences of the film where Tom is seen wearing a woolen hat, his long hair is visible at the back in many shots. This is despite his character having short cropped hair throughout the rest of the film. (see trivia)
When the Baptist and Hatchet Harry are killed and Tom is looking around the office, both the Baptist and Hatchet are visibly breathing although they are supposed to be dead.
In the van when Bacon finds the traffic warden, there is an extra arm seemingly coming out of the floor of the van.
When Rory Breaker and his crew back the van in front of the boys' house, it backs up onto the curb. When everyone is shot and Nathan starts up the van, it's off the curb.
As Tanya, the dealer, is explaining the game of Three Card Brag she completes the initial deal. She accidentally exposes the bottom of the deck which would be visible by all players as a 7 of diamonds. This should have resulted in a misdeal.
When Hatchet Harry and Barry the Baptist are killed, neon lights can be seen against the dark background through the window behind Harry, but they would only be visible at night, though the event occurs in daytime as seen in the next shot outside the building when Eddie and Tom enter.
The position of Gloria's head changes when Plank, after accidentally sitting on her, asks if Gloria is 'compis' and moves in toward her face for a closer look.
Before Dean is shot by Hatchet Harry, there is clearly visible a prop between Dean's body and shirt for blood splatter. Even after Dean's been shot and is lying outside Hatchet Harry's office, the prop is also visible under the shirt.
When Tom is explaining the cheque scam to Soap and Bacon, in the last shot of Soap and Bacon the liquid level has lowered in the glass in front of Bacon but Bacon is not drinking from it. In the same shot there is also an extra cigarette butt in the ashtray although Soap doesn't stub out his cigarette.
When Rory Breaker's henchmen visit the dope house in the evening or at night (it's dark), they find J who has come around and screaming in pain. Which means that the police still hasn't come to the house. This is highly improbable, since there was a shooting there during the day. Dog's men had fired shots with the very loud Bren gun in two separate occasions, and Gloria also fired it after them, emptying out the magazine. Even if there was nobody else in the building, the shots would've been heard from at least a couple of blocks away, and the police would have come.
When Gloria fires the Bren gun, there are around 60 shots heard, yet the Bren she is using appears to have a 30 round Magazine
When "the neighbors" are torturing some unknown criminals - the leader is standing on one guy, hitting golf balls at another guy who is hanging upside down in his underwear. The first golf swing is using a metal wood, then he asks for a five iron. However, the club handed to him is clearly not a five iron, but another metal wood.
Just before Plank gets shot in the neck with the air rifle, he is looking to his right with the left side of his neck exposed. But when he is shot, the close-up shows him holding the right side of his neck.
When Tom speaks with Nick the Greek about buying weapons, Nick the Greek is playing a fruit machine. The sound of the machine is heard, but it clearly isn't working.
Dog closes his eye a fraction of a second before the Bren gun is fired while in the cage.
When Winston opens the security gate, he leaves the keys in the gate, then after Dog butts him and drags him to the stairs, Winston still has the keys in his hand. When he gets to the top of the stairs, the keys are no longer in his hand.