When Dr. No's men pass by in a boat and shoot at the shore where Bond, Honey and Quarrell are hiding, their commander shouts "We'll be back - we'll be back with the dogs!" into a megaphone, which has an echo effect. He then lowers the megaphone and waves his arm as he shouts "Full Speed Ahead!" - which has the same megaphone/echo effect, despite the lack of megaphone use.
The Beretta pistol that Bond has at the briefing is a model 1934 and was never chambered for .25ACP as mentioned. It was only chambered in .380ACP (9mm short) which is more powerful than 7.62mm (.32ACP) that Boothroyd states the Walther (also available in .380ACP) is chambered for. When Q branch gives Bond his Walther PPK, it's really a Walther PP.
During the rocket countdown, the commentary from Cape Canaveral says that this is the launch of the MA-7 (Mercury-Atlas 7) mission. This was Scott Carpenter's flight as part of Project Mercury. Just a little later the rocket is reported as being at its full weight of 240, yet the launch weight of the Atlas rocket was only just over 100 tons.
After Honey is finished being showered and decontaminated, the technician passes a Geiger counter over her and reports, "Practically zero - she's clean." However, in the very next shot, from the side, Honey is plainly seen removing her hands from the machine used to decontaminate radioactive particles from the fingernails. This action is redundant.
We see James and Honey washing themselves in the river after avoiding the dogs. Honey has clearly taken off her swimsuit top and is wearing only her white shirt. As they run to the bank, she is not carrying her bra/bikini top, but in the next scene, when their shirts are both dry, she has her bra/bikini top on under the white shirt.
The car that Felix Leiter hops in at Kingston International Airport is a 1961 Chevrolet Impala pillared sedan, but the car that is used in the chase scene on the highway (in which 007 is in a 1957 Chevrolet Bel Air convertible), is a 4-door pillarless sedan.
When shooting at the "dragon", Bond's gun changes from a Walther PPK to a Colt .45. His gun also goes into slidelock (indicating empty) twice while shooting, and without visibly reloading, continues to fire.
When James lights his cigarette and Sylvia asks to raise the stakes, he first has removed the cigarette from his mouth and placed his hand on the shoe, but when he says, "I have no objection, " he is just taking it out of his mouth. The camera cuts to his back, and his hand is back on the shoe. The cigarette jumps between his hands and mouth several times.
One of Bond's traps in his room is his briefcase; he puts talcum powder on it. When he is done he sets the case down on the right side of the table. To the left is a mirror and by the mirror is an assortment of perfume bottles and a shaving bag. When he returns, the contents on the table are reversed exactly, and the perfume bottles are replaced by a magazine.
When James Bond sits down with Annabelle at the club, the camera strap is around her neck. When they do a close-up shot of her the strap is gone. In the next shot, James is taking the strap and the camera from her neck.
When Dr. No crushes the gold Buddha statue at the dinner table with his hands, it falls off the table onto the floor. However, when a wider camera angle is shown, right before the guard takes Bond to the elevator, the gold statue is back on the table.
When Bond is waiting for Professor Dent to arrive at Miss Taro's house, he pulls out his Walther PPK to attach the silencer. In closeup, however, the pistol is actually an FN Browning 1910. This can be verified when the camera zooms in Bond when he's attaching the Braun silencer to the pistol. You can see the letters FN inscribed on the grip of the pistol. The pistol was used in the scene because the film production's weapons specialist couldn't find a silencer that would fit the Walther PPK that Bond was issued.
When Bond and Dent are together and Dent tries to get the gun with his foot, there are several continuity issues: the gun is very close to Dent's foot when there is a close-up, but then further away in the next image. Also, there are wrinkles in the cloths and then they are flat. In addition, after Dent has "had his six shots," the slide on his Smith & Wesson semi-automatic is in the back, or "empty" position; when he later tries to grab the gun, the slide is in the forward, or "loaded" position.
When you see Bond in his hotel room for the first time, there are two bottles on the table, a clear one and a green one. When he reenters the room and checks his traps, the green bottle has disappeared. Bond takes a bottle from a drawer but that also is clear so what happened to the green one?
When Bond is driving to Miss Taro's house in the hills, he's being chased by a couple of people in a LaSalle hearse. We see Bond and the hearse swing round a corner and head toward the camera. We then see a shot of Bond and then another shot of the cars coming around the same corner (you can tell by the small bush on the right side of the hill next to the road). In fact the same location is used in 3 separate takes from the exact camera position.
After Bond and Honey's encounter with the patrol boat on the beach she retrieves her shirt from her shot-up boat and they both run off into the jungle barefoot. In the following scenes they're both wearing shoes.
During Bond's shootout with the "Dragon" on the beach, he uses three different model handguns. His Walther PPK, changes to a Colt Government Model, then to a Browning Hi-Power, and then back to a Walther PPK.
When Dent sneaks into the room and shoots the pillow 6 times, you can see him after he notices Bond. When he does come in, you can see his tie really messed up and the back of the tie you can see the label. When you see the shot again, when he sits down, the tie is tucked in and it is straightened.
After Bond's dinner with the good Doctor, in his cell, he uses one of his slippers to beat on the wire grate after it shocks him. When he crawls through the opening, he has slippers on both feet. Also, he may have lost or gained a slipper when moving through the drain tubes.
First time Bond speaks to Quarrell painting on the beach.
Quarrell puts the paint on the reversed boat, close to a paintbrush.
Seconds later, the paintbrush has moved a little far away of the paint.
Also, the paintbrush in the paint has moved from left to right.
At the airport on Jamaica, when Bond uses the telephone booth, you can see the lighting and crew members reflected in the glass door as he opens it to walk in and out, also when Felix opens the door you can see them again.
When Honey tells Bond that the one shell alone is worth $50 in Miami, she tries to shield them from him. A piece of equipment is seen bobbing at the bottom of the screen. The full shots of them reveal no such piece of equipment.
When Bond has the conversation with Felix in the bar, Annabelle smashes a flashbulb and scratches Quarrel's face with it. Flashbulbs of that era were filled with oxygen to provide a good flash. Unfortunately they often exploded so they were covered with a thick plastic coating to prevent this. If the bulb was smashed the plastic coating, which is clearly seen as burned and blistered when she smashes it, would have kept the sharp edges safely inside and Quarrel would not have been harmed.
The Bren Gun seen on the patrol boat has no magazine attached when it is first shown. Later, when supposedly firing, the magazine, which fits on the top of the gun is being held in place by hand ....and backwards.
The speedometer of the '57 Chevy shown in the chase scene is actually that of a '57 Ford. Also, the close-up shows a black steering wheel and dashboard whereas the Chevy has an obvious red steering wheel and dashboard.
Further into the Cell escape scene as Bond crawls through the vent pipes, he has to secure himself to avoid being washed away by a sudden rush of water coming through the pipes. Water cannot be flushed through air vents.
After waking in a cell after being knocked unconscious during dinner with Dr. No, Bond is electrocuted while trying to punch out a grate in the air vent. He then uses one of his rubber soled shoes as a glove to insulate his hand. As Bond was standing on a bed wearing rubber soled shoes, he would have already been insulated against the electricity guarding that vent.
When Bond is sliding down the pipe, a gush of water sweeps over him. However, later, when he emerges from the pipe, he is in a hallway with no trace of the water. However, in the last few seconds of this sequence, he is clearly climbing a diagonal shaft toward the ventilation grille. Though it is odd for air ventilation for an underground facility to share a shaft with some kind of waste-water disposal system, the water would not likely have come out of the ventilation shaft.
Bond sets traps in his hotel room, including the closet, but is wearing a darker suit when we see him check them later. He changed suits in his room and reset the traps afterward; we didn't see it happening because it wasn't interesting.
When James is riding in the 57 Chevy convertible from the airport to the hotel, a close up of the engine temp gauge indicates "C" for cold. But by this time, the engine would be at operating temperature with the dial centered between "C" and "H."
When Bond and Honey are made to take showers to clean them of any remaining radioactivity, they are meant to be naked. When Honey gets out of the shower a man holds a towel up for her, but if you look closely you can see that she is wearing a flesh-colored swim suit.
When Bond is driven away from the airport, the camera shows the speedometer of the car at 70 mph, and other elements of the instrument panel. The temperature gage is flat in the C position, indicating the engine is not running .
When Bond and Quarrel are shooting at the dragon, Bond's first shot misfires; you can see the hammer fall, it doesn't fire, he shoots a look at Quarrel as if to draw attention away from the mishap, and continues to hold the gun on aim as if nothing happened.
At Government House, Bond shows the commissioner the 'cyanide Cigarette'. This is clearly just a cigarette broken in half, no phial of Cyanide or missing tobacco that the driver would have had to ingest to get poisoned.
The goof items below may give away important plot points.
The hearse used by the Three Blind Mice When they shoot Strangways' secretary and to chase Bond on his way to Miss Taro's house is a LaSalle (circa 1939), which is also used in the rear-projection shots for the car chase. The vehicle which goes over the cliff, however, is a British Humber or a Packard (circa 1941). You can tell them apart easily as the Humber/Packard (the hearse that goes over the cliff) has headlamps at the extremities of its wings, while the LaSalle's headlights are mounted much closer to the radiator grille/hood.
At the end when Bond and Honey are in the small wooden boat there is no tow rope visible. When the rescue vessel shows up and announces they will give them a tow a heavy duty tow rope is seen draped over the stern.
Realistically, overloading a nuclear reactor of that size would have resulted in an explosion that would have spread radioactive fallout over Jamaica, Cuba and Haiti, and rendered portions of Jamaica uninhabitable for over a century. But naturally, this is Bond movie physics and things don't work as they would in real life.
Before Bond shoots Dent, he says "That's a Smith & Wesson and you've had your six." Dent's gun is clearly a Colt Model 1911 which holds seven rounds (or eight with one in the chamber). Also, after Dent fired into the bed, the slide locked back indicating the weapon was empty so there was no reason for him to pick it back up and try to shoot Bond with it.