Revealing mistake: Many times throughout the car chase in Las Vegas between Bond and the cops, you can see skid marks where they tried earlier stunts with the cars on those points on the road. The most obvious is when Bond pulls away from the Sheriff after he approaches the car.
Audio problem: In the scene at Willard Whyte's house where Thumper and Bambi are fighting Bond, Bond gets thrown into 3 cylindrical statues. Just as the shot cuts, you can see the last column beginning to topple but there is no sound as it crashes to the floor in the next shot.
Continuity mistake: When Bond climbs the Whyte House to get to Willard Whyte, he climbs a large overhanging structure, leaning out over the main part of the building. But in the previous day shots of the Whyte House there is no such structure to be seen.
Factual error: The first laser beam was not generated via a diamond, as Willard Whyte says. The first functional laser device, which was constructed by Theodore Maiman, used a ruby rod.
Revealing mistake: In the final fight scene, Mr. Kid is set on fire by Bond and jumps overboard. What hits the water, though, is a dummy: it floats on the surface right after hitting the water (a human body would sink for a few meters before it comes up again).
Revealing mistake: On the oil rig, when Bond tells Tiffany to "shoot 'em" after she gets the gun, three bad guys run towards her. A helicopter drops a bomb in front of them, taking them out, but watch the guy who is the furthest away. The bomb lands a good 20 feet away from him, far enough away not to do any harm. But he crouches a little and stays up, then he looks at his other two crewman a bit puzzled, and then falls down a bit later as he finally realises what he was supposed to do.
Factual error: Shady Tree opens the coffin with bare hands - and keeps his hand on the lid for 6 seconds - notwithstanding the fact that it was just pulled out of a blazing furnace and must have been incredibly hot to touch.
Visible crew/equipment: When Bond and Tiffany are talking while looking at the fish, he suddenly rolls her on her back, saying "I'm on top of the situation". As she turns you can clearly see a plaster (band-aid) carefully placed to cover any...er...accidental revealings.
Factual error: In Blofeld's offshore control room there's an Earth-globe turning under a model of the satellite, to illustrate its orbital groundtrack. The way it's arranged, however, shows an orbit which is impossible. It shows the satellite tracing a groundtrack over a constant latitude. The only instance in which this is possible is if the orbit is directly over the Equator, whereas the model shows it over a latitude well within the Northern Hemisphere.
Continuity mistake: In the opening sequence when Bond runs over and pulls the chain to release mud onto the guy rising up to shoot him, mud clearly splatters all over him as he dives to the floor. When he gets up, his suit is spotless.
Continuity mistake: When the car chase enters a car park there is a blue car in the bottom left corner (from the overhead shot), next to the trailer which Bond makes his escape over. After Bond escapes the car is white (I think) and may also be pointing the opposite direction.
Other mistake: When the man at the start is thrown through the room and his head hits the wall, the picture briefly freezes.
Visible crew/equipment: When the helicopters are attacking Blofeld's platform, at some points you can see a little black spot moving in the background. It is the radio-controlled helicopter which filmed them from behind.
Continuity mistake: Bond shoots the Blofeld-copy with a climbing hook. But when did he reload his gun? (And why? He was done climbing).
Revealing mistake: During the car chase, Bond weaves through a car park, and a police car can't make the turns, sliding into a wall. The wall's covered in one specific point by what looks like a large pale wooden cover, which the police car just happens to slam into exactly.
Revealing mistake: Blofeld is played by an actor that is not bald (Blofeld was bald in 2 previous episodes). He is also played by Charles Gray, who played the part of one of the good guys in You Only Live Twice. [Not really a mistake, given that Blofeld doesn't have to conform to certain physical characteristics. However, an actor playing a good guy then a bad guy over the space of two films rankles a bit...]
Factual error: When Bond is in the trunk of the car, being taken out of the lower level of the White House, a trap door opens out into the desert. There are two Saguaro cacti shown, one on the trap door and one in the distance. Saguaro cacti do not grow wild any where near Las Vegas.
Factual error: When Bond is inside the oil rig, the shots switch from the satellite control room to the satellite itself orbiting. When the satellite fires at the underground missile, it's orbit direction reverses. Then, when it fires at the Russian sub and the Chinese military base, it stops before it fires. This is impossible, as Newtons 3rd law states that for every action there is an equal and opposite reaction. For the satellite to reverse or stop, boosters would be needed at the front of the satellite (of which there aren't any) to counter it's speed. And even if they were there, the direction change and stop wouldn't be as sharp as the movie shows.
Factual error: When Mr. Wint and Mr. Kid assassinate the doctor in the South African desert, they use a scorpion. Scorpions are poisonous, but the sting is more like a bee's, and woudn't kill a healthy adult.
Other mistake: When the car chase starts in Vegas in a close up of the two policeman chasing them the driver is wearing sunglasses and the background is badly dubbed. Silly thing to wear when it's nighttime.
Chosen answer: Blofeld and Spectre has enough diamonds for the laser he is building to hold the Earth hostage. In typical Spectre fashion, since he is finished with the operation, he wants to leave no loose ends that could tie Spectre into the mix.
Zwn Annwn