Plot hole: Why did the Gatekeeper and Keymaster (the dogs) have to possess Dana and Louis? From everything we see, the dog statues are at the top of the building, and the demon dogs break through. Then they go and destroy half the building to find people to possess. They wait a while, Louis gets taken to the Ghostbusters, and Dana stays in her apartment. Then even later they go back to the top of the building, and stand exactly where they were standing after changing from the statues where the lightning changes them back into the demon dogs. What was the point of them leaving, possessing people, then coming back?
Continuity mistake: At about the middle of the film, when the Ghostbusters are rising to fame and are appearing on the front of newspapers and magazines, the photograph on the front of the New York Post is taken from the end of the film, just before the four of them cross the streams from their proton packs. (00:39:37)
Revealing mistake: In the ballroom scene, when Slimer is flying around the chandelier, he disappears for a few frames when he reaches the far side. [This animation is mentioned in the DVD commentary. The film makers were generally unhappy with the entire animation and the fact that the representation of the apparition did not resemble those previous and that the movement was very unconvincing.] (00:35:05)
Continuity mistake: When Winston gets hired, Venkman and Stantz have just come back from a job. They're covered in slime and Venkman's smoking. Ray gives Winston an armful of traps. We then cut to Venkman chatting to Dana after a rehearsal, so we assume it's later, maybe even a different day. After that scene though, we then cut back to Stantz showing Winston (wearing the same shirt) what to do with the traps, and Venkman talking to the guy from the EPA. Venkman's got the same slime pattern on his shoulder, and is still smoking. Looks like the Dana/Venkman scene was in the wrong place. (00:42:00)Jon Sandys
Revealing mistake: Near the end of the film when the Ghostbusters take cover in a small corner and come up with the "cross the streams" plan, look closely at Peter's proton pack, you can see that it is a foam "stunt" pack as there is a small sticking out part that keeps squashing against the wall behind him. (01:32:25)
Plot hole: The Ghostbusters cross their proton pack streams which results in a tremendous explosion. The next scene shows the blast pushing Mr. Sta-Puft away from the building. A second later another scene shows the explosion radiating outward from the roof. The only part of him shown over the edge of the building is his head and his right hand. To get all over the Ghostbusters, marshmallow would have to be blown in the opposite direction against the force of the blast. It makes sense that there was marshmallow all over the street, but how did it land on the Ghostbusters?Grumpy Scot