Revealing mistake: When Gene's bodyguard (the one with the moustache) shoots Slasher and Duke, just before Slasher is shot the bullet hole effect is visible on her forehead (sightly concealed by make-up) just before the actual 'shot'.
Revealing mistake: When XXXX is in Greenwich Park with Mr. Lucky and he gets shot, Dragan shoots at the grass in front of XXXX. Grass is thrown into the air, and you can see white smoke coming from an explosive for the special effects.
Continuity mistake: When XXXX is awakened by Dragan's phone call, there is a gun lying on his pillow. In the overhead shot the gun is pointing in one direction; in subsequent shots it is pointing the other way. (00:40:45)
Factual error: When the pills are being recovered in the mock police raid, we see, several times, an observer watching through binoculars. We see his eye enlarged, despite our looking the wrong way down the lens.
Deliberate mistake: Slavo and Dragan are supposed to be Serbians but they speak Romanian.
Continuity mistake: In the scene where XXXX and Lucky are in the park waiting in order to assassinate Dragan - after Dragan shoots Lucky and is talking to XXXX on the phone, the bag that Lucky was resting his gun on changes position between shots.
Continuity mistake: In the scene in the park where XXXX and Lucky are waiting in the bush - when Lucky looks through his telescopic sight at Dragan it appears to be raining, however, when we return to the wide shot of the two of them in the bush, it appears to be a rain-free day.
Factual error: (At 56:26) XXXX is dropped off by Eddie Temple. As you'll notice the car drives straight off (at 56:31). This not is possible as the road that XXXX lives at 7 Queens Gate Mews, Kensington is a cul-de-sac (no through road). The car would not have been able to go anywhere.
Continuity mistake: When Tammy is undressing, she pulls off her top and is not wearing a bra. Moments later, when pulling on her nylons, the bottom of a black bra can be seen at the top of the frame. This is the same bra that she puts on to finish her outfit.
Continuity mistake: When Lucky is with XXXX looking for Dragan at the top of Greenwich Hill the cross hairs in the telescopic sight appear and disappear between shots.
Continuity mistake: When XXXX and Gene are drinking at the coffee table, from the side shot the bottles are at opposite sides of the table but from underneath they are side by side.
Factual error: The scene at the start of the film shows XXXX and his assistant making drugs. In the voice-over, XXXX mentions that his assistant has a double first in industrial chemistry from Cambridge, and is doing this job to pay off his student debt. This is wrong on a number of levels. First of all, there is no such subject as industrial chemistry to study at Cambridge, nor has there ever been such a subject. Only Chemistry is taught. Secondly, Chemistry is a single honours subject: you would only get at best a first in it, not a double first. "Double first" means you scored top marks in two separate subjects you study - for example if you read French and Spanish together, that would be double honours. This is not the case however for chemistry. Lastly, the statement about paying off student debt makes no sense given the film was set in Britain. At the time, student fees were no more than £3000 a year ($3800) so in a four year course you would end up paying only £12000 ($15200), plus living expenses. But loans are only repaid once you're earning above a certain limit, and then proportionally to your income - they're not "due" like a standard loan. It therefore makes no sense for the assistant to be working such a dangerous and illegal job if all he wishes to do is pay off his student debt - he has evidently worked with XXXX for a long time given how much XXXX trusts him.
Continuity mistake: After XXXX places the telephone call before being abducted from his apartment by Eddie Temple's thugs, he throws down the cell phone on the bed. In the next shot when Tammy comes out of the bathroom, the cell phone is gone.
Visible crew/equipment: SPOILER: When XXXX gets shot at the end of the movie, a simulated blood packet is visible being shot at him, not a bullet.
Continuity mistake: Lucky's body changes positions several times after he is shot dead.
Continuity mistake: When XXXX goes to lunch with the boss at the clubhouse at the beginning of the movie, the position and composition of golfers on the green and golf bags propped at the flagpole changes between the aerial and ground shot.
Continuity mistake: SPOILER: The pistol featured on the movie cover is not the identical gun used during Gene's flashback. Although it's said to be the same murder weapon, both guns can be set apart when Gene opens his hidden cache of weapons. One gun has a noticeably blue handle.
Continuity mistake: When XXXX and Gene are drinking at Gene's apartment, the whiskey bottles change positions between shots.
Deliberate mistake: The scene where XXXX gives Dragan the package next to the statue in Greenwich park is incorrect: Greenwich park is surrounded by fences and shut at night between 6pm in the winter and 10pm in the summer when it is still light.
Continuity mistake: When XXXX and Gene are drinking whiskey at Gene's flat, XXXX fills the glass closest to him first, but when the camera switches through the table, the glass closest to him is empty and he has filled up Gene's glass first.
Answer: Because the logo's a car registration plate and a number fits that structure better than just letters.