The idea of unusual heat in the museum rendering thermal cameras useless, came from Director John McTiernan's Predator (1987). In that movie, McTiernan's thermal cameras began to fail, when the jungle temperature broke ninety degrees Fahrenheit (thirty-two degrees Celsius).
The film originally showed Crown breaking the backing of the Claude Monet painting in order to fit it into his briefcase. However, John McTiernan later decided that audiences might be put off if they saw him in some way damage the painting, so he edited the scene so that it only showed Crown putting the folded painting into his briefcase, and figured most people wouldn't catch on to the fact that the briefcase was half the size of the painting.
When Crown (Pierce Brosnan) sees Catherine (Rene Russo) off after they meet at the museum (when he donates the painting), he gives the limo two taps on the hood to signal the driver. This was Pierce Brosnan's trademark send-off to Fred (Blake Clark), the driver, in his breakthrough role in Remington Steele (1982).
When Catherine sees Anna (Esther Cañadas) in Thomas' bedroom, Pierce Brosnan was instructed to physically hold onto Rene Russo, so that she would have to struggle to get away from him. Russo did not know that Brosnan was going to hold on to her.
The scene of Crown racing a catamaran replaced a similar scene in the original script (and the original movie) that was set at a polo match. John McTiernan deemed a polo match to be too much of a cliché, and wanted a scene that conveyed more action and excitement, and not just wealth.
John McTiernan decided to change the heist from a bank robbery, as was seen in the original 1968 version, to an art heist, as seen in this version. McTiernan felt that at the time the film was released, audiences would be less forgiving of Thomas Crown if he staged two armed bank robberies for fun, than if he staged an unarmed art heist.
The final conversation between Detective McCann and Banning, in which he essentially excuses her from the investigation, so she can chase down Thomas Crown, was not in the original script, but added about halfway through filming.
In the scene where Thomas Crown is dancing at the party, his tie is untied on his tux, and the top buttons unbuttoned. This is because at the time, Pierce Brosnan was under contract to play James Bond, and a rumored stipulation of that contract, was that he could not wear a tuxedo in any non-James Bond movies.
The Metropolitan Museum of Art refused permission for their interior to be used in the film, so the filmmakers used the New York Public Library, a few blocks, away for many interior scenes, and a soundstage for the rest. The exterior of the Metropolitan was shown several times, with permission from New York City.
The glider is a Schempp-Hirth Duo Discus, a German high performance two seater. However, it is physically impossible to reach from the rear seat to the front in flight. So this was arranged in the studio. The glider was flown by Thomas Knauff, a famous glider pilot from the U.S. In the original 1968 film, there are similar scenes in another glider, a Schweizer 1-23, an American high performance glider from that time.
In the elevator after the boardroom meeting, Thomas Crown and his subordinates quote from the Leonard Cohen song "The Stranger Song": "Ah, you hate to see another tired man lay down his hand like he was giving up the holy game of poker."
The suit designer, who appears in Thomas Crown's office, is Gino Campagna, who has been featured on CNN's Richard Quest's segment. He is also the designer responsible for the look of the clothes in this film.
Despite the fact that the museum is never mentioned by name, in one of the first scenes, a proctor is seen wearing a blazer with "Metropolitan Museum" clearly visible on it. It is also noted on the crate carrying the "Trojan horse".
The helicopter used in the theft, a Sikorsky S76, actually has a lift load of almost four thousand pounds, not six hundred pounds, as stated by Catherine (Rene Russo), which is a character goof, and not a goof on the part of the filmmakers.
The Claude Monet paintings used in the film, "San Giorgio Maggiore at dusk" and "Wheatstacks", are reproductions, and were supplied by "Troubetzkoy Paintings" in New York City, New York. What's more, the originals are not owned by the Metropolitan Museum of Art in New York City. "San Giorgio Maggiore at dusk" is owned by the Bridgestone Museum of Art in Tokyo, Japan, and is currently on display in the National Museum and Art Gallery, Cardiff, Wales. "Wheatstacks" is at the Getty Museum in Los Angeles, California. The painting Crown admires and calls "his haystacks" is Vincent van Gogh's "Noon: Rest From Work (After Millet)", the original of which is in the Musée d'Orsay in Paris, France.
The catamaran that Thomas Crown is seen racing in Long Island Sound, is a D-Type Catamaran. The earliest Class D catamarans were designed and built by individual amateur designers as early as 1963. Richard Karcher of Watchung, New Jersey, built either USD#1 or #2 at the time. His "D" boats were sailed on Barnegat Bay, New Jersey for several years on an experimental basis. Richard also designed and manufactured several other types limited production catamarans at the time, one of which was considered as the official Olympic Class Catamaran, and participated in the trial in England. Due to the vast amount of power that this design represented, no "production" versions were ever produced, and interest and research into this Class waned. Many years later in the 1980s, interest in this extremely fast and highly unstable yacht design was revived by California-based aeronautical engineers, who tried to break inshore multi-hull speed records. Today, there are only a handful of them left in the world.
The teacher leading the students states that the painting, which is subsequently stolen, is credited with starting the impressionist movement. Actually, it is Monet's Impression, Soleil levant (Impression, Sunrise).
Robert D. Novak, a political columnist for the Chicago Sun-Times and co-star (or frequent guest star) of such political talk shows as Crossfire (1982) and The McLaughlin Group (1982), has a cameo appearance as a museum proctor.
The trivia items below may give away important plot points.
The last line of the movie, where Catherine leans into Thomas on the plane and whispers, "Next time, I'll break both your arms", is a reference to Magritte's painting "Son of Man", to which is alluded, and shown numerous times during the film, and who Thomas pretends to be, in the final museum scene. A subtle feature of the "Son of Man", is that the man's left arm appears to bend backwards, as if broken at the elbow. Since Thomas models himself as the "Son of Man", she is remarking that she'll break his right arm as well as the already broken left.
The second painting that comes up missing, and is given to Catherine Banning at the heliport, is "Banks of the Seine at Argenteuil" by Edouard Manet, 1874, and the real painting resides on long term loan to the Courtauld Institute Gallery in England. It is never explained in the movie how it was taken, but hints do exist in the original draft of the script.
The final heist consisted of men wearing bowler hats, trench coats, and carrying briefcases, to confuse the surveillance team. This was similar to The Heist (1989), another Pierce Brosnan film, where a heist at a horse track involved multiple men wearing Hawaiian shirts and straw hats.