Continuity mistake: While at the pool hall, Mary indicates that the sign in the window describes Larry perfectly. A close-up shows it reads 'Out To Lunch', but the next wide shot shows it reads 'We're Closed'. (01:01:45)
Continuity mistake: When Bond is flying over China and landing on the sea by Scaramanga's island, you can see that his plane has two floats - one on either wing. But in the shot where he is heading for the beach, it is clearly seen that the left float has gone! (01:28:40 - 01:30:55)
Continuity mistake: During Inspector Kemp's visit at the Frankenstein manor, Frankenstein is playing darts while he is having his conversation with Kemp. He throws the first dart at the bottom 10, but by the time he throws the second dart at 7, the first dart he threw at 10 is now at the bottom of 18. (00:56:20)
Continuity mistake: The small plane's pilot identifies the aircraft as 232Z. But in the exterior shots, the aircraft's identification is N9750Y. (00:35:00)
Other mistake: In the original version of the film there's a mistake in the opening credits where Colin Blakely's name is misspelled as Colin Blankey.
Continuity mistake: The people inside the elevator disappear in the wide angle. (01:57:21 - 01:57:51)
Revealing mistake: When Gittes visits the orange grove and crashes into the tree, you can see that a steel plate has been placed around the tree to protect it.
Continuity mistake: When Julie is taking off her shoes, after taking off her first shoe, her body is hunched to the right. But in the next shot, she is standing upright. (00:10:47)
Visible crew/equipment: After Lightfoot steals the Trans Am, when he first encounters Thunderbolt on the run, he swerves into the field, and in a shot from inside the car, a piece of filming equipment on the hood of the car is visible through the windshield. Then Lightfoot hits Dunlop with the car. (00:07:50)
Continuity mistake: When the boy stabs the man in the back with an ax while they're chopping firewood, the position of the ax changes between shots. In the first shot, the ax is vertical because the boy is behind the man. In the next shot, the ax is horizontal as if the boy is on the right side. (01:06:53)
Continuity mistake: After the general is killed, there's a close-up on the figurines. Two are broken with just the feet left, the third, the rightmost, at the waist. When the second victim was murdered, we saw the killer break just its head off, the statue to the right of the halved one. The following shot shows the statues in that order, with the addition of third broken one in rightmost position. (00:34:15 - 00:42:15)
Other mistake: When Hyman Roth's assassin runs at the airport, he is turning around with one (of two) bullet holes already in his jacket before the sound of any gunfire. (03:10:50)
Continuity mistake: When the guys use the key to steal the car, its back license plate number is 4N-4290, but when Chico pulls into the drive-in, the front plate number is SV-5875. Then when Chico reverses the car, the front license plate number is 4N-4290. (00:42:40)
Revealing mistake: When Butt falls behind the suitcases, a mattress to soften the fall is visible.
Continuity mistake: When Waco Kid is lying down on hay bales at the end of the film, there is no horse. All of a sudden when he's invited somewhere by Sheriff Bart, a horse appears. (01:33:50)
Suggested correction: It is true that the horse suddenly appears, but Jim is reclined on hay bales, not boxes.
For future reference, this is what the "change the entry's wording" option is for.
This entry is about the sudden appearance of a horse. It has nothing to do with The Waco Kid reclining on boxes nor does the entry say he was reclining on boxes. It says that he's reclining on bales of hay.
It did say bales of hay - I've left the correction and "change wording" comment online for a bit for informational purposes.
Revealing mistake: During the quake, a mother is seen having a plate glass window fall on her face while her daughter screams. Before the mother turns around to show us the gore, look close and you can see a shard of glass already "placed" in her face before the fake glass falls her. Additionally, while not a "mistake", it's clearly a "stuntman" portraying the mother. The face and yelping give it away.