In the orgy scene, when Bill enters the room where there are several people on the long table, there are two people in cloaks (one standing and one sitting) obscuring the camera's view. In the reverse shot of Bill, these people are no longer there in the background. These people were added virtually in post production, following the death of Stanley Kubrick and the movie's subsequent NC-17 rating.
After Nick Nightingale writes "Fidelio" on the napkin and Will Harford picks it up, the position of the word changes and also its spelling.
When Bill and Alice discuss her near-infidelity, the ashtray they were using when smoking the joint appears and disappears from the bed, the tapes and CDs are in different positions, and Bill's hand jumps off Alice's hip.
When Dr. Bill Harford leaves Domino's apartment the second time after meeting Sally, her roommate, he is shown walking down a Manhattan street and passes buildings with numerical address 36, 37 and 38, all on the same side of the street. However, in New York City, even numbers are always on one side of the street and odd numbers are always on the other side. He could not have passed the street addresses 36, 37, and 38 on the same side of the street. In fact, an earlier scene on the same street shows an address 25 on the opposite side (shown when Dr. Bill Harford notices that he is being followed by a man).
When Bill is going to the room where Marion is, there are two tables in the corridor, with a sculpture on each one. When Carl arrives some minutes later, the sculpture on the first table has disappeared.
The end credits state in parenthesis that the cast is listed in order of appearance, but such a statement is inaccurate. For examples, Nicole Kidman is actually the very first to appear, and Madison Eginton shows up the day after nighttime festivities at the Zieglers' house where several adult characters are introduced.
In the morgue, three chest X-rays are displayed on wall-mounted negatoscopes for no reason. Medical students are taught to always switch them off after use (to avoid wear and tear of and damage to the devices) and file the X-rays (for privacy).
When Bill hands Victor the newspaper clipping regarding Amanda's overdose, it is torn along the top but not along the right, which should be the case since it came from the New York Post.
During the final shopping scene, the price of £25 (i.e., British Pounds) is visible on the 'Magic Circle' box, despite the scene ostensibly taking place in New York City.
On closer inspection of the scene in question, the Magic Circle box does not display £25 but actually the number 125 which is presumably the number of items in the box.
On closer inspection of the scene in question, the Magic Circle box does not display £25 but actually the number 125 which is presumably the number of items in the box.
The maid addresses "Carl" as "Mr. Thomas" when he enters the apartment. Thomas Gibson plays Carl, but presumably this means the character is "Carl Thomas."
It is very unlikely Bill would have gotten all that information from the front desk clerk at the hotel. The clerk explained what happened as if he were really there, when in reality, he is probably a manager and was not there as this event occurred in the wee hours of the morning. even if he is not a manager, he is working the 7 am-3 pm shift, in which he still would have not been there at that time. The clerk might have been working a double shift.
When the nude masked woman walks up to Bill Harford with the masked man, in the first shot (with her hair behind her), she is one actress, but in the next shot (with her hair in front of her), she is an entirely different actress. One can easily tell this even though she is masked and naked.
When Dr. Harford returns to the mansion in the country, it is summer with leaves on the trees behind him.
The same gang-"tagged" mailbox is used as a prop on several different back lot "streets".
When Bill Harford is reading the newspaper about the drug overdose, the headline actually reads "drugs overdose" (UK usage) instead of "drug overdose" (USA usage).
When Alice and Helena are doing story problems, Alice says "Joe has two dollars fifty," which is a UK/Australian construction, as opposed to the more American "two dollars and fifty cents" or "two fifty".
When Alice is telling Dr. Bill her confession about the naval officer, the audio has her saying "you and I made love" while her lips move to say "we made love". In the context of the following sentences it's clear she was making love to Dr. Bill, but from the preceding lines her "we made love" could have ambiguously referred to her and the officer.
In the overdose scene in Ziegler's bathroom, crewman with hat distractingly reflected in the shower chrome trim (reports are the video transfer has made this less obvious).
When Alice goes to the bathroom cabinet, the camera is reflected in the mirror when she opens the cabinet door. It and the cameraman are hidden under a white sheet, with just the black, square lens showing through.
A camera shadow is seen on the ground, to the right of Bill, during his first night walk.
When Milich opens the door to the room where he finds his daughter, the legs of the steadicam operator are visible.
Reflected in the bedpost during the love-making scene.
Bill Harford arrives at Rainbow Fashions by taxi from the Sonata Cafe, and, as he talks to Milich, Gillespie's Diner can be been seen across the other side of the street. Earlier in the story, it was seen that Gillespie's is next door to the Sonata Cafe; there's no way he would have taken a taxi just to cross the street.
UK road signs and road markings are seen in "New York" throughout the movie.
When Dr. Harford visits a New York morgue, British electrical sockets can be seen in the hallways.
At around 2h 5 mins One can see the stop sign is on the left hand side of the road. If the action takes place in New York, USA then the sign should be on the right hand side.
In the pool room scene, reflected in the green light when Victor says "OK, he had a bruise on his face."
When Bill goes to the Sonata Jazz Club, outside the club is a poster of the four members of the band with their names. It lists Larry McVay as the drummer and Kip Fleming as the bassist. But inside the club, after the band is done playing, Nick (the pianist) introduces the band saying "Larry McVay on bass and Kip Fleming on drums."
When Victor Ziegler (Sydney Pollack) refills his and Dr. Bill Harford's (Tom Cruise) Scotches during their final conversation in the Red Pool Room, Victor switches glasses with Bill. (This possibly could be intentional.)
At Victor's party, when Alice responds to Sandor's explanation of why women get married, she momentarily slips into an Australian accent (which is Nicole Kidman's native accent) when she says, "Fascinating."