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 the demon breaks out of the statue on Dana's apartment building, it breaks away the right paw. When we see the statue after the demon is out, both paws are intact. (00:48:55 - 00:51:55)
Continuity mistake: Dana gets home and puts down on the table the paper bag with food and her coat as she answers the phone. She takes her shoes and pants off and the camera cuts away to a different angle where the coat and the paper bag have changed position. (00:51:00)
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: During the party, when Louis throws the coats on the gargoyle's head, its horns are visible from the front shot, but covered in the immediate angle from behind. (00:53:20)
Continuity mistake: After Louis asks if anybody wants to play Parcheesi at his party, there is a lady sporting a red vest behind him, standing in front of a wall with framed photos. Two shots later, she's standing in front of the kitchen next to a bespectacled man. The very next shot, she's teleported back to where she was initially, in front of the wall. (00:53:25)
Continuity mistake: When Vinz Clortho sprints off the building's front doors to chase Tully, the distance between the passers-by changes. (00:54:05)
Continuity mistake: Trying to escape the demon dog, Tully trips over a chair and bangs against the windows of the restaurant. You can see in the first shot that the maitre d' (the guy with grey hair and stache, wearing black) is looking at him. But in the reverse shot, he's smiling at the patrons at the table, and only a moment later raises his head to check out what the fuss is about. (00:54:35)
Continuity mistake: When the possessed Dana asks Peter for the second time "Are you the Keymaster?", Peter comes in; notice that Sigourney Weavers' left hand is still at the top of the doorframe, in the reverse shot it's suddenly down. (00:56:10)
Continuity mistake: During the scene with the possessed Dana in bed with Peter, the pillows rest at different heights against the bed's headboard. (00:57:30 - 00:58:40)
Continuity mistake: When Venkman is in Dana's bedroom the quantity and quality of light coming through the window changes between shots; look at the side of the window when he is counting down, for instance. (00:58:30)
Continuity mistake: When the terror dog ruins Louis' house party, a man cowers behind a dining chair. In the shot immediately following his closeup, the chair has magically sprouted armrests. (00:59:35)
Continuity mistake: Dealing with Tully, Annie Potts says one rather oddly foreshadowing line to Harold Ramis about his death, and then clings to him. Ramis puts a hand on her shoulder, and the position is different in the next shot. (01:02:00)
Continuity mistake: When Egon tries to prevent Walter Peck from shutting down the protection grid, he has Janine and Vinz (Louis) behind him. You can see that Vinz is raising his right arm, but in the next shot his right arm is now lowered down. (01:06:15)
Continuity mistake: The silly bureaucrats cut power to the containment grid, which is about to blow up. Everyone runs away from the building; there are two main camera angles on the exterior, but they are obviously not in continuity - in the closer angle, natural light shines on the street to the right, while in the wider/higher angle that side of the building is in the shade. (01:07:50)
Continuity mistake: When the Ghostbusters are heading for the building, there's a wide view of New York bathed in a sunset light with a red and blue sky. In further close-up shots, there is a clear sunny light everywhere. (01:15:20)
Suggested correction: Most likely the result of the supernatural clouds forming around the building.
Continuity mistake: When the mayor orders Walter Peck out of his office, you can see that he is pointing his finger at Peck, but when the camera angle changes his hand is nowhere to be seen. (01:17:45)
Continuity mistake: When the Ghostbusters arrive at the skyscraper, a guy with a bulky walkie-talkie appears/disappears between shots. (01:19:25)
Continuity mistake: When the heros arrive at Dana's building, they're saluted by a crowd. If you pay close attention, you'll see the same extra in two different positions (he's the young - and very "happy" - guy wearing a grey suit and a purple tie). (01:19:30)
