Factual error: About 20 minutes in, the group find a Welsh miners' group in the phone book. The character who is making the call speaks the first two digits of the phone number: "0, 1,..." The movie is set in 1984, when the dialling code for that district was "0639" In that year, "01" was the code for London, not Wales.
Factual error: When Jess meets her father and Martin on the embankment it is twenty to five in the afternoon, however this is between New Years Day and Valentines Day - it would be dark at this time of day in these months.
Factual error: The film makes use of a real Broadway theater, the St. James, which is on West 44th St. When they leave the stage door, the actors are next to the Edison Hotel, which is on 47th St.
Continuity mistake: In the scene where James and Ben are interrogating Jay at the pawn shop, watch Jay's shirt. It changes from green to black.
Factual error: When the guy is talking to him on the phone and the Russian smashes it on the floor, the phone smashes and the battery comes out but the guy other end can still hear him. (01:04:00)
Other mistake: In the flashback to Richard's childhood, when he looks from the door at his dad randomly shagging a party guest, the door appears open wider in the POV than it is in the other shots, where the opening barely fits his head. Besides, with the head in that position, he wouldn't see the door handle as shown. (00:02:00)
Continuity mistake: Felix pushes the fire alarm button and exits the building. As his buddy Danny reaches him, it's obvious that multiple takes of the scene have been made, since some extras that were meters ahead of him are just passing him by at the very first cut. (00:04:30)
Continuity mistake: Jay is mopping the floor after promising on the phone to his dad that he'll bring his non-existent fiancee to the wedding. He tries to talk one of the nurses into joining him. While doing so, he stands before her leaning on his mop with his left hand on top, which switches to the right hand between shots. (00:06:40)
Revealing mistake: When the woman is tied to the bed, she is holding the ropes, and the rope isn't tight on her right hand; she can easily escape. (00:20:10)
Continuity mistake: Vincent and Oliver are eating ice cream, Vincent's ice cream cone repeatedly changes levels of ice cream left in his ice cream cone as he eats it. (00:48:00)
Plot hole: When Mr. Shepherd arrives at the school he learn Joseph's (the student's) name but loses his memory. When they are telling him the nativity story Shepherd says "this Joseph" when referring to the student, but he shouldn't remember it.
Continuity mistake: As the two assistant workers walk away from the prison building at the end of the first day, Charlotte Gainsbourg's grip on her folders switches between shots.
Continuity mistake: There is a scene where she accidentally stabs someone - she gets blood all over her from the stabbing and then in the very next scene is wearing the same shirt without blood stains.
Continuity mistake: The protagonist just unveiled to his boss the "nest" ad, to which he suggests some not-so-minor changes. Luca Argentero is holding the drape in two very different ways between shots (first with bunched cloth sticking up top, then simply folded). (00:05:00)
Continuity mistake: Stretch takes the licence plate off the limo just before it's stolen. When he's clinging onto the bumper as it's being towed, the plate is back on.
Continuity mistake: The glass that was dropped and shattered on the floor had a different pattern of fragments when Mitch [Robin Williams] knelt to clean it up. Most obvious was that the majority of shattered pieces settled toward Mitch's feet but were on the opposite side of the largest piece of glass during clean-up. There's also a "stupidity" in the way Mitch wiped up the glass - pressing down on the thin towel (apparently to entrap fragments), which is most likely to result in getting pierced. (00:01:40)
Continuity mistake: Before Jesse's plate is placed on the table, the salt and pepper shakers are about a width apart. They are almost touching for a while, then back to being spaced apart. (00:10:20 - 00:11:00)
Continuity mistake: In a scene at a night club, Colin Firth's friend has a glass of red wine in his hand and then he has a glass of white wine.
Continuity mistake: When Hugh Grant writes "Protagonist" on the board, the writing changes depending on the shot, most noticeably the G - sometimes it looks a bit like a backwards question mark, other times it's so slanted it looks more like an S.
Continuity mistake: When Dex sees "his" son for the first time, the kid in close-ups is playing with the toy that dangles from above, and there's a toy football by him. In the wider angles none of the above is happening. (00:38:40)