Continuity mistake: When TC steals the Monet, he places the painting in the briefcase and closes the case breaking the frame in half and thus ripping the edges of the painting. When at home he opens the briefcase and the frame is obviously crooked but when he holds the painting up to place it above the fireplace it is perfectly intact and the painting is not damaged.
Continuity mistake: In the opening sequence, when Crown decides to walk and has "Jimmy" meet him at the office, he is almost run down by a truck. First of all, the truck has to skid to a stop, yet there is a car no more than ten feet in front of it when they change camera angle. Why was the truck going so fast in the first place. Secondly, when Crown motions for the driver to pass, the same car is still stopped directly in front of the truck, yet the truck speeds off in a way that it should smash into the car in front of it.
Continuity mistake: When the "thieves" are preparing the impressionist wing and inform Thomas Crown that the exhibit is closed, Crown responds with "It's only a quarter to five". Shortly after when the surveillance footage from the time of the robbery is being reviewed, the time stamp on the monitor says 5:54. I doubt that the whole robbery took 1 hour 9 mins, when the time in the movie was around 3 minutes.
Continuity mistake: When TC and Catherine Banning are having breakfast together at TC's house, Paul brings Catherine her green shake to drink. In one of the first shots, the glass is only about two-thirds of the way full, however, in the next shot, when she goes to take her first sip of it, the glass is almost filled to the top. The color of the green shake also changes slightly.
Continuity mistake: When Thomas and Catherine are having breakfast and his servant Paul brings Catherine's special "green" drink, it changes colors. When Paul has it on the tray and sets it down on the table, it is a very deep olive green. When she goes to actually drink it, it's now a light pastel turquoise blue color.
Continuity mistake: When TC opens the briefcase to steal the Monet, the thumb of his latex glove is ripped wide open, which would leave fingerprints. After he places the painting in the briefcase, the next shot shows him closing the brief case and the glove has magically repaired itself.
Continuity mistake: When they land in Martinique, and are on the airstrip loading up the vehicles, their luggage and the painting go into the second vehicle, a shiny black jeep. However, when they show the aerial shot of them climbing the mountain to Crown's house, the jeep is now painted in camouflage colors.
Continuity mistake: Thomas Crown comes into the police station to identify the thieves. As he is getting ready to leave, Catherine eavesdrops on his conversation as she fixes herself a cup of coffee. She then watches him out the window, drinking her coffee, as he runs to his car. The paper coffee cup changes from a purple swirl design with a little bit of green to a blue and white, geometric border with what appears to be an Asian design.
Continuity mistake: In the first scene in the gallery when TC is admiring the Haystacks painting, he is preparing to eat a croissant. In the shot looking at him face on, he maneuvers the croissant into position in the bag it is in, so that he can begin to eat it. However, in the next shot - a longer distance profile shot - just after he answers Bobby's question, he is already chewing on a mouthful and starting to tear another piece off.
Continuity mistake: The theft occurs on one of the hottest days of the year, as pointed out by the guards. When Katherine arrives that night, she is wearing a coat. The investigation lasts a week or two, and throughout that time, they wear jackets and even top coats. Katherine's breath is frosty in the air a week or so after the theft. The weather apparently went from really hot to really cold in a week or so - NY weather may fluctuate a bit, but not to that extent.