Mickey's tattoos seriously fade during the final fight scene. This is most notable when Turkish is talking to him in the corner after the third round and when Mickey imagines he has been knocked into water.
Near the end of the film, Turkish and Tommy are driving and Turkish is drinking a chocolate milk (the markings on the milk carton are brown, indicating chocolate milk). However, when Tommy tosses the carton out the window and the milk lands on another car's windshield, the milk is white, not brown.
In the first fight, Mickey's cigarette appears/disappears several times
When Lincoln is talking to Sol in the shop about his diamond, he has his finger on his forehead in the surveillance camera, but in the next shot, his hand is not on his head.
The exterior shot prior to the scene where Turkish, Tommy, and Gorgeous George are playing cards in the caravan before the last fight is obviously taken from the beginning of the movie since it shows the door in place and Charlie outside cooking sausages. (In several scenes in between the door is clearly standing against the caravan after Turkish pulled it off.)
Bullet Tooth Tony states that his gun has Desert Eagle point 5-0 (.50 caliber) on the side of his gun. The gun is in fact a Mark I Desert Eagle (noted by teardrop style safety) which was never chambered for .50. Also note that he fires a total of 8 rounds in the pub, which suggests that his Desert Eagle is actually a .44 model rather than .50.
When Boris is talking with his brother, his two statements are pronounced in Russian and incorrectly subtitled in English. The first statement is subtitled as "So, what should I do?", which is actually pronounced "Ya posmotryu shto mozhna zdielat" and means "I'll see what I can do". The next statement is subtitled as "It's OK. I know a couple of guys," which is actually "Da, ya ponimaiyu," meaning "Yes, I understand."
In the closing credits, "Gypsy kids" is misspelled "Gyspy kids".
When Uncle Avi is flying to London, and his passport gets stamped by an immigration officer, the stamp has a date on it, but apparently it's a simple rubber stamp, so the date can't be changed.
If Sol and Vincent's guns were able to fire blanks, they would be able to fire real bullets. If there were any sort of barrel blockage, the gun would have been blown apart by the blank since they contain considerably more powder than a regular cartridge, just no bullet.
The scene at 1:34:12 is supposedly recaptured at 1:35:49 but there are differences with respect to the reactions and positions of the characters. In crime movies, it is common to have this type of discontinuity, to represent realistic eyewitness disagreement.
During the opening credits when Franky Four Fingers is introduced and his nickname is being explained, he's shown holding cards in his hand with a missing finger visible. It appears that when the shot follows his hand laying the cards down, all the fingers on that hand are present, but the hand belongs to Turkish, not Franky Four Fingers, and this can be viewed by slowly advancing the movie one frame at a time. The different skin tones are a dead giveaway.
When Boris the Blade visits Vinny and Sol in the pawn shop, Vinny holds up the diamond. In the next shot, Boris the Blade asks Sol where the diamond is, and Sol says it is in the locked briefcase. Vinny had time to put it there (and can be seen doing so) and lock the briefcase, though it was admittedly not a very bright thing to do; then again, Vinny isn't very bright.
When Boris first talks to Sol about the job, he offers him £50,000. When he comes to pay Sol and Vinnie for the briefcase, the amount has lowered to only £10,000. However, when Boris hears that there wasn't much cash at the bookies, he offers them the £10,000 to HELP the situation. In other words, he realizes that he promised £50,000. As a shady character, it is normal for him to cheat in this way.
In the back of the truck after the diamond heist in Antwerp, Frankie gives his gun to another man. During this exchange it can be seen that Frankie does in fact have all ten fingers.
When Frankie Four-Fingers is talking on the phone, while changing/trying on suits, the "missing" finger reappears briefly in one shot.
During his phone call from the pub, Bullet Tooth Tony says they're in The Drowned Trout, however the real name of the pub - The Jolly Gardener - was clearly visible as they walked in.
When Frankie Four Fingers is holding up the diamond broker in Antwerp in the opening scene, he is seen holding his Smith and Wesson 681 revolver. The trigger is nearly fully back in the trigger guard, indicating the gun is cocked, but the hammer is down, instead of also back.
At one point Bullet shoots Boris with two rounds from his pistol. There is a flash from the first gunshot but there is no flash from the second.
When Sol, Vinny and Tyrone are in the car after crashing into Franky Four Fingers' van, you can hear the patter of rain on the car roof but there is no rain falling on the windscreen.
When robbing the diamond broker in Antwerp, a fire exit sign in one of the corridors appears firstly in French and secondly, in smaller letters, in Dutch. However, Antwerp belongs to Flanders, the Dutch language area of Belgium, and the public signs have to be first and foremost in Dutch.
When Tony intercepts Vinny and Sol outside Brick Top's place, he acts as if he knew they were going to be there. This, even though he had no idea about their deal with Brick Top. (This is, however, explained in a deleted scene.)
Avi refers to Boris as "this goyim." "Goyim" is plural; the singular word for non-Jew is "goy." This is a common error made by non-Jews, but terrible for a Jew to make.
As Bullet Tooth Tony, Avi and Avi's bodyguard leave Doug the Head's, the bodyguard opens the door of Tony's Jaguar before Tony inserts the door key to unlock the doors.