Continuity mistake: When Dana struggles with the literal arm-chair, one of the arms pops out of the top of the right armrest and a clawed hand clutches Sigourney Weaver's face. Change of camera angle, and not only she is struggling against the demonic limb in a different position, but the hole is gone from the top of the armrest, the arm is sticking from the side. (00:51:45)
Continuity mistake: The lighting in the scene with Venkman stalking Dana outside the concert hall is inconsistent. For instance, when he quips "I've got hundreds of people dying to abuse me", Dana's stiff friend leans against a fountain that is bathed in sunlight. Mere moments later the section of the square is in the shade. (00:43:10)
Continuity mistake: There's a crumpled piece of paper on the shelves behind Peter when he argues with Walter Peck in his office. As you can observe when Peck sits down, the paper is in a different position in the close-up compared to the wider angle. (00:47:40)
Continuity mistake: The famous Twinkie scene; notice that when Egon utters the line "Let's say this Twinkie represents the normal amount of psychokinetic energy" etc, there's a cut mid-sentence. Harold Ramis is holding the bar with 3 fingers in the first shots, 4 in the second. (00:48:05)
Continuity mistake: When Winston gets the job after the very tough and thorough interview process, he walks up to Ray. Between shots, the messy cables of the traps Ray is holding are in a completely different position, and he holds the paper sheet at a different height. (00:42:20)
Continuity mistake: When Peter gets slimed, the very marketable goo stains his uniform completely messing up the right half of his chest. In the ballroom scene the uniform is practically clean on that side, but got dirtier over the left shoulder.
Continuity mistake: When Ray Stantz slides the trap across the ballroom to catch Slimer, the cord is curled, but it is perfectly tense in close-up. (00:37:05)
Continuity mistake: When Venkman radios Ray to tell him about the ghost, look at the cart in the background when Ray answers; the mess does not look the way it looked in the earlier close-up; there's less stuff on the partially knocked down scaffold and the table ricocheted away from the wall but here the flowers are back on it. (00:33:20 - 00:33:45)
Continuity mistake: When the hotel manager says he won't pay the 5k, the trap is facing him with the top side. As it cuts to the Ghostbusters faking to just walk back in and release their catch, the trap turned 45°. (00:38:50)
Continuity mistake: Dana is at the Ghostbusters' who just tested her with a device. When she says that she does not believe in 'those things', Ego picked up a cheez-it and brings it to his mouth. In the next shot he's not the one with a snack to his mouth, Ray is. (00:23:25)
Continuity mistake: The guys have just been thrown off campus. A liquored-up Peter walks Ray to the right explaining; "I believe that everything happens for a reason." Before the camera cuts away, you can see the head of a girl with a red ribbon in her hair that is going down the stairs. Next shot and she hasn't even set foot on the first step yet. (00:14:45)
Continuity mistake: The future Ghostbusters don't have a clue yet what to do with the ghost of the librarian. They send Peter first, who tries to work his charm saying "Hello. I am Peter." Harold Ramis in the background is pointing the camera at a different height/angle between the two shots. (00:11:30)
Continuity mistake: Venkman is questioning the shocked librarian about possible use of drugs. Director Delacorte in the background is half turned towards them, but he's facing them directly in the close-up when Venkman says "Just asking." (00:08:05)
Continuity mistake: The shot that introduces the existence of the Ghostbusters is a shot of the door of the "Paranormal Studies" laboratory inside Columbia university. It's a door that opens to the left and bears a glass panel with the names of the 3 scientists. When the shocked kid and Ray use it though, the door swings the opposite way. And when the Ghostbusters get back to their lab and find the Dean there, it's a double door with no glass, which was a prop built just for that opening shot. (00:02:45 - 00:13:10)
Continuity mistake: When Slimer flies off after Ray shot towards him the first time, the cart rolls away; you can see that the champagne bucket was not knocked down by the messy explosion. When the cart crashes in the wall, the bucket enters the frame already lying horizontally. (00:33:10)
Continuity mistake: When Peter sets foot into Dana's house, in the establishing shot of the room you can see two pink pillows on the armchair. Between their first and second appearance the pinker one in front has slumped. (00:24:15)
Continuity mistake: Egon is done testing Dana with the electrodes on her temples. He walks past her pronouncing a line; " I wouldn't rule out clarvoyance." There's a cut during the sentence, and in the first shot Dana is looking up at him, in the second she is looking at the floor. (00:23:20)
Continuity mistake: The librarian is carting away books that are (for the greater length of the top shelf at least) leaning away from her. Cut, and they are positioned differently, about one third towards, a part in the middle away, and again towards her. (00:00:50)
Continuity mistake: When Dr. Venkman investigates Dana's refrigerator, there is a Corning dish and a can of Coke side-by-side on the top shelf. The camera cuts twice, and there is suddenly another item (looks like lunch meat) that appears in front of the Corning dish and the Coke can.
Continuity mistake: When the Ghostbusters capture the green ghost, they emerge from the ballroom. The manager then asks,"Did you see it? What is it?" and you can see he has his hands by his side, but the next shot shows him with his left hand reaching for the handkerchief in his top pocket.
Answer: He places it on the altar just after they believe they have vaporized Gozer with the proton packs. At this point, thinking the ghost to have been destroyed, he sets it down as he believes the job is done and he will not need it.
Jazetopher