Continuity mistake: When Tilly falls after her fatal encounter with Oddjob's hat, she lands on her back. When Bond comes over to kneel over her body, it is face down.
Other mistake: In the scene where Tilly Masterson is running through the woods away from Bond and Auric's men, Oddjob throws his hat at her. It hits her in the neck and she simply falls over and dies. However, a few scenes before Oddjob throws his hat at the statue and cuts the head clean off. Shouldn't Tilly have been decapitated?
Other mistake: When Felix and his partner are following Odd Job to the airport, thinking they are tracking Bond, they are supposed to be in Kentucky but palm trees are visible in the background en-route.
Continuity mistake: When Bond and Tilly Masterson stop at the garage after her car is ruined by the Aston, we see her wooden case on the rear parcel shelf of the DB5. She gets out and so does Bond, yet when he reaches in to give her back the case he only just reaches in with his arm. There is no way he could reach the case.
Factual error: After Bond make the tanks explode, he goes to see a woman. A man enters the room with a bar in his right hand. James sees that in the eyes of the woman, but the image is not reversed like it should be.
Continuity mistake: When Bond duels with Tilly's car, before crashing it, a blue-screened mountain always appears behind him, despite the landscape being totally different.
Continuity mistake: When Goldfinger loses his card game, he gets mad and snaps his pencil in half. I have doubts that the pencil would make such a loud noise, but either way, there is no way Bond could have heard this, seeing as we're to believe Jill's radio only goes one way.
Continuity mistake: In Switzerland when Bond chases Tilly, the weather suddenly changes from almost clear skies to quite overcast.
Continuity mistake: In Fort Knox, when Bond is crouched about to grab the hat, he moves closer to it between shots.
Continuity mistake: In the teaser, when Bond has come out of the water and climbed up the cliff, right after he kicks the guard he is seen running away. In that frame you can see he is wearing leather shoes with light brown leather soles - which are completely dry. He was not wearing those in the water.
Plot hole: Goldfinger wasn't planning on Mr. Solo breaking away from the rest of the gangsters before Goldfinger could have them all killed by the nerve gas so it makes no sense that there would already be a truck from the stud farm waiting for Oddjob to drive back with the remains of the crushed car. It also begs the question if Oddjob had to drive the truck back to the farm where is the guy that drove it to the junkyard in the first place?
Revealing mistake: The rear projection behind Bond as he is driving through Geneva doesn't match the scenery outside his car.
Continuity mistake: Near the start when Bond and Moneypenny are talking about gold, she throws his hat at the hatstand. The top of the hat is facing left as it flies offscreen, but when the shot cuts to it landing it's turned itself around so it can catch properly on the hook. Plus it lands on the hook furthest from the door, but when Bond leaves he picks it up from a closer hook.
Continuity mistake: When Bond comes around on the plane and meets Pussy for the first time, she tells him they are flying SW over Newfoundland. The clock on the restroom door shows 10.05am. Later, when she announces arrival in Baltimore in 55 mins, the clock is now showing 2 .45pm giving arrival time of 3.40pm. Flying time would have been approx 3 hours, arriving at 1.05 pm.
Revealing mistake: Before Goldfinger is sucked out of the plane, the flying cushions (superimposed on a chroma) magically vanish.
Revealing mistake: When Oddjob is killed and falls face-down, he turns his head to the left a second before he smashes it against the floor.
Continuity mistake: When Oddjob arrives at the junkyard, it's a cloudy day and the car casts no shadow; however, a shot later, from a different angle, it's a sunny day and there's an 8 o'clock shadow beneath the car.
Continuity mistake: After Bond hits Oddjob with the stick, Oddjob launches him face-down, but from the next angle Bond is landing and sliding face-up.
Revealing mistake: When Bond grabs a huge stick to attack Oddjob, the first wide shot behind Bond is of a very obvious stuntman with a square face and a prominent jaw. Stunt also visible after Bond jumps and grabs Oddjob's neck, when he is launched against the wall.
Revealing mistake: When Oddjob throws his hat at the statue and the head comes off the head falls on top of the arm and breaks it. Obviously this was not meant to happen as there is a quick edit in the film before the arm falls completely off (notice the trees behind the statue suddenly freeze).
Chosen answer: They're not. Q was just indicating to Bond that these were the wing machine guns, he wasn't stating which was which.