Factual error: In the first frontal shot of Percival's Porsche following Lorraine, virtually every car parked at the side of the road is from after 1989, one of them not even being on sale until 2007. (00:16:10)
Continuity mistake: In the scene where Ashley says that they've got CDs in the tanning salon you can see Ashlyn keeping a cream tube on the table with her right hand. In the next shot you see her continuing the same action with the left hand.
Factual error: It is not possible to have a conjoined twin of the opposite sex. They are similar to identical twins, which are always of the same sex, in that they are formed from a single zygote. In the case of conjoined twins, the zygote fails to divide normally.
Suggested correction: There are always exceptions to the rules and, although VERY rare, it IS possible for conjoined twins to be - rather, end up being - different sexes. There are about 10 documented cases. In one case, is my understanding the conjoined twins started out as males but a genetic mutation (or something) occurred and one male lost his Y chromosome, thereby developing into a female with no ovaries. (The now-female twin would have so-called Turner Syndrome.) I don't have any sources to quote off-hand.
The male would have lost his Y chromosome after the zygote "split", but he was a monozygotic male.
Continuity mistake: When the Dude is in Jackie Treehorn's estate, he pencils over a pad of paper to see what Jackie wrote down while he was on the phone. He then hurriedly crumples up the piece of paper and shoves it in his wallet. Then, when we see the Chief of Police of Malibu looking through the contents of The Dude's wallet, the paper is there, neatly folded in fourths.
Factual error: The priest says that St. John saw the number 666 in his vision, but it was actually 999 inverted. St. John wouldn't read modern Arabic numerals like we do, it would be Roman numerals. The number 666 would actually be DCLXVI. (01:05:40)
Continuity mistake: When Silent Bob renders the demon disabled by using the anti-odour spray, you see him take the spray out of his coat and spray with his thumb. However, it cuts to a front view, and he is clearly seen using his index finger. It then cuts to Bob's rear, and he is, again, spraying with his thumb.
Continuity mistake: When Nicholas Cage is being escorted to fetch the roll of film from his car, there are a few scenes where the accountant is holding a gun to Nicholas's head. When the camera is directed at the accountant, two hands can be seen grasping the gun, but when the camera is facing Mr Cage, initially there are two hands but after the next switchback there only appears to be the one! (01:20:50)
Continuity mistake: At the end of the film Mickey Rourke smashes up a pile of ice, which mysteriously reappears in its unsmashed form seconds later.
Visible crew/equipment: When you see the plane flying to Tibet you can clearly see the blades of the helicopter from which the shot was taken at the top of the screen. (00:49:20)
Visible crew/equipment: When Helen and the Candyman are in the psychiatrists' office, Candyman flies out of the window backwards. If you look very carefully, you can see the harness that pulls him backwards.
Other mistake: When Prot visits the doctor's house, he thanks the wife and the camera is zoomed into his sunglasses. The reflection of his glasses shows the doctor looking at him, but the doctor is standing behind him. (00:53:40)
Continuity mistake: When Fletch and Stanwyk first meet and Stanwyk asks Fletch to come to his home and hear his proposal, Stanwyk is wearing a suit/tie on top but is wearing jeans on the bottom. In the next wide shot as they leave the beach, and again in the next scene as they arrive at Stanwyk's house, he is wearing suit pants. (00:04:50)
Suggested correction: Stanwyck is never wearing jeans in any of the scenes, he's always wearing matching suit pants.
Factual error: In the scene where there is a train passing, the cars are marked "Burlington Northern." There was NO Burlington Northern until 1970, 7 years AFTER the shooting.
Visible crew/equipment: After the ship's captain delivers the Falcon to Sam Spade's office, he collapses on the leather sofa in the foreground. Just after Spade's secretary says, "Is he ...?", the shadow of someone's head passes over the sofa.
Continuity mistake: The tape is labelled "Vincent Grey" in the first shot, but the label disappears in the next shot. (01:11:32)
Continuity mistake: In the flashback to the death of the headless horseman, when the horseman's steed gets shot and falls to the ground, the blood and the wound are on the right side of the horse...later in the scene when the horse is seen again, the wound is on the left side of the horse. (00:16:45)
Revealing mistake: This is toward the end of the movie. The scene where Dr. Giggles has a waiting room full of his victims. If you watch closely, you will see the blonde corpse blink her eyes.
Continuity mistake: Watch the Mustang blow up at the beginning of the movie. It looks to be about an 88 GT convert. When it is shown after the explosion it changes to an 86. Two completely different looking cars. Check out the headlamps. (00:17:50)
Continuity mistake: When Emma is protecting John at the top of the stairs and he says, "I didn't kill anyone," her hand is at her side. In the next shot, her arm is raised in front of him. One shot later, it's back at her side. (00:23:40)
Continuity mistake: At the carnival, the glass of lemonade goes from half drunk to full. (00:32:20)