Revealing mistake: When Ray kicks and breaks the pipe in the underground, the prop was obviously put together to break at the flimsiest touch; it's not just a corroded or even cracked pipe, the two parts are not even of the same color, they were never a single piece to begin with. (00:25:40)
Revealing mistake: In the courtroom scene, when the sample of slime begins to bubble and react to the judge's malevolence you can plainly see that an inflatable mechanism situated under the jar is responsible for the wobbling. (00:32:00)
Revealing mistake: During the sequence where the ghosts knock the courtroom chairs in the air, you can see that some chairs have one leg that looks oddly 'loose' or with something sticking out (as interviews with the technical cast members clarify, each chair had an extension part that went into the floor and was launched up by an air mortar). (00:34:45)
Revealing mistake: When Venkman is shooting at the ghost in the courtroom, if you look closely at the pillar his proton stream hits, you can see the area that is supposed to explode before it actually does. (00:35:25)
Revealing mistake: A Ghost Runner scares the people having a jog in the park. When you first see this peculiar ghost (who even checks his own pulse, funnily enough) the extras react to him with timing wildly off; the ones further back in the curve react when the ghost has already passed them by, but turn towards the middle of the track as if he were right there. One of the last people reacting is a woman who didn't even make it to the curve in time to see anything. (00:37:20)
Revealing mistake: When they gather around to watch what happens when you put the slime in the toaster, you can see when the toaster starts popping that it has little pneumatic pistons attached to the bottom, making it jump. When the toaster gets picked up off the table you can view its power cord which is entirely too big - more likely air lines. (00:41:15)
Revealing mistake: Janine is wrapping up work at the phone and puts a cover on the computer screen. The monitor is plugged in, but the desktop is not. (00:55:20)
Revealing mistake: With his unexplained amazing pyrotechnic and telekinetic powers Vigo lights up the Ghostbusters' dark room and traps them locking the door. Winston barges in and luckily his very mundane fire extinguisher easily puts down the hellish supernatural flames; it's so effective that it also extinguishes the flames in the foreground without him ever pointing the thing at them. (00:57:30)
Revealing mistake: When Ray, Winston and Egon are underground looking for the river of ooze, there is a scene where they break down a small wall of rocks. Ray then sits on one of the rocks and it bends under him - it's rubber or foam. (01:01:50)
Revealing mistake: When Oscar is standing backwards on the ledge, he moves frame by frame like a robot, revealing it's a stop motion effect and not a real baby. (01:15:00)
Revealing mistake: People are running away from the movie theater, terrified by the ghosts. Are they really though? The girl at the head of the line (she moves towards the screen from right to left, almost blocking the path of another notable extra that waves around a popcorn bag) just can't keep herself from laughing. Same for a guy that tries to whip the animated fur into submission using his scarf (although one could argue in that case that it's such a weird predicament that a bystander could be amused). (01:19:30)
Suggested correction: Exactly, some people are like the Ghostbusters, they ain't 'fraid a no ghost, which is why they laugh.
Revealing mistake: The second mink in the coat that comes alive is a blatant glove puppet. (01:19:50)
Revealing mistake: During the montage of the ghosts running rampant in NY, one of them in the shape of some sort of dinosaur pops through the archway in Washington Square. It's a ghost solid enough to have to squeeze through the opening and not just disappear through the marble, but when it roars menacingly the optical effect does not work and the superimposed monster does in fact pass through the solid stone. (01:20:10)
Revealing mistake: When Lady Liberty walks down the street, the four Ghostbusters inside its crown are replaced with very obvious dolls. (01:30:05)
Revealing mistake: When the Statue of Liberty is about to smash the museum's glass dome, the shot outside is really bizarre: The Statue is standing on a park, with a pink cloud covering what is supposed to be the museum. Yet the lower part of the cloud plus the people around it, show that there is no building nor any foundations there: Just a superimposed pink cloud over an empty field. (01:31:35)
Revealing mistake: When Vigo repels the Ghostbusters after they shot him, the lads bounce against the background...that bounces back against them, despite being 'solid concrete'. (01:34:10)
Revealing mistake: When Vigo drops the baby in the end of the movie, you can see it is a doll. (01:36:20)
Revealing mistake: When the [superimposed] pink slime and the bending tub try to attack Dana and Oscar, watch the tiles on the wall in front and you'll notice that they're not being reflected, just an empty space.
Revealing mistake: In the aerial angle of the Statue of Liberty walking down the streets, watch behind it: it is very evident where the matte painting was inserted: The street colour differs and the objects have way less definition.
