(at around 10 mins) When Patience climbs out of the window to rescue Midnight she is standing above a main road, yet when she climbs out of the same window and steals the motorcycle (at around 41 mins), it leads to an alley.
Patience and all of her co-workers are wearing the same outfits two days in a row.
(at around 1h 14 mins) The length and styling of Tom's hair changes for one scene in the middle of the movie. Throughout the movie he sports a fairly closely cropped haircut, but in the scene directly after the sushi-restaurant he has a markedly longer wavy cut and different length and shaped sideburns. In the very next scene (bedroom) he again has the much shorter cut.
(at around 41 mins) The helmet appears and disappears during Patience's initial ride on the motorcycle.
(at around 10 mins) When Patience climbs the windowsill to rescue Midnight, she is on the second floor, about 25 ft above the ground. When she enters her apartment by the fire escape from the backyard (at around 25 mins), it's on the first floor, no more than 10 ft above the ground.
(at around 43 mins) When Catwoman encounters the thieves stealing the jewelry, one of the thieves has a Desert Eagle. The standard magazine clip for a Desert Eagle can only fit 7, 8 or 9 bullets, depending on the caliber. The thief shoots 11 bullets without reloading.
Ever go by a jewelry store at night? Ever see jewelry in the window? No? That's because insurance companies make them take all of the good stuff out of the windows and the display cases and store them in the safe until the next day, when they are put back on display. Which means there could be no burglary as depicted in the movie.
(at around 43 mins) When the jewelry thieves are shooting at Catwoman in the jewelry store, they fire a total of 16 rounds between them with two shotguns, without reloading. The shotguns have standard magazines, so at most, they would have four in the magazine, and one in the chamber. Thus they could have fired ten rounds without a reload.
(at around 1h 28 mins) When Catwoman is running the chains through the Hedare trucks, she is seen feeding chain over the drive axle of a truck. In the next scene when she drives away only the front left steering tires are pulled off by the chain.
Detective Tom Lone does not seem to have a partner when conducting investigations, or when he's in his office. As a federal agent, he would be required to have one.
In the movie intro, the word "Pyramides" is shown, rather than "Pyramids". In fact, the image in which the word appears corresponds to a closeup of an old, antique Ptolemy map of Egypt, published by German geographer and cartographer Sebastian Münster. The illustration first appeared in 1540 in his Latin edition of Ptolemy's Geographia, which is why the name labels are written in Latin. "Pyramides" is Latin for "Pyramids", just as "Cairum" (also seen in the same image) is "Cairo".
(at around 42 mins) After realizing her transformation, Catwoman rides her motorcycle through the city streets at high speed. After passing through an intersection, other cars pass through the intersection at extremely high speed, revealing that the film had been sped up.
(at around 42 mins) When the first burglar in the jewelry store smashes the glass cabinet, the glass is already shattered when his shotgun is still halfway in the air.
(at around 20 mins) Patience flees security at Hedere headquarters at night by escaping through the sewers. As she is running through the subterranean tunnels there is lighting to show her movements, when it would actually be pitch black.
Patience says that she "went to art school". A person does not "go to art school - not if they want a serious graphic design job. They get a university degree in their field. There is a lot more to graphic design than what is shown in the film and only a small percentage of it is about art.
The Beau-line makeup is said to harden your skin like marble after excessive use, but your face will disintegrate if you stop using it. Sally was a frequent user of the cream, and although she displayed the symptoms described by Slavicky (headaches and fainting spells), she does not seem to have rock-solid skin, nor does her skin melt off after Patience takes her bottles of cream away and disposes of them.
(at around 28 mins) When Patience returns Midnight, Ophelia tells her that, "She's an Egyptian Mau, the rarest of breeds." The Mau is, in fact, somewhat rare, but there are other breeds (Selkirk Rex, Korat, Somali and Havana Brown, for instance) that are far less common. Cat Fancy Magazine lists eleven US catteries specializing in Maus. The breed was introduced to the US in the 1950s, not 1940 as mentioned in the film, although its lineage dates back well over 2,000 years - a spotted Mau like cat is clearly seen in hieroglyphs, and there is the belief it is the cross between a domestic and wild cat about 3,000 years ago.
Ophelia refers to her cat Midnight as 'she' and 'he' in different scenes.