(at around 1h 23 mins) In the birds-eye view of the Ghostbusters walking through the wreckage of the penthouse, there is still sunlight bouncing off the building despite the fact that New York is supposed to be covered by a big black cloud.
(at around 54 mins) When Louis runs toward the Tavern on the Green he says, "I'm going to bring this up at the next tenant's meeting. There's not supposed to be any pets in the building," but his mouth doesn't move.
(at around 1h 35 mins) Ray declares the phenomena they are witnessing may be as important an event as "the Tunguska blast of 1909" in Siberian Russia. This occurred on June 30, 1908, not 1909. (It is noted elsewhere in this section that Ray refers to Revelation 6:12 as 7:12 and refers to the Sumerians as being civilized in 6000 BC rather than the correct 4000 BC; getting numbers wrong is a character trait of his.)
(at around 1h 3 mins) Ray quotes a Bible verse, which he says is Revelation 7:12. In fact, it is Revelation 6:12. Also, Ray forgets some words, while Winston adds words that aren't present in the verses.
(at around 4 mins) Near the beginning of the film Venkman is conducting an experiment, in which he says he is using Negative Reinforcement. Two test subjects guess the symbol on the back of the card. Venkman administers electric shock for wrong answers, and gives praise for correct answers. (Of course, he's cheating, but on with the content critique.) Psychologically and Scientifically speaking, Negative Reinforcement is the subtraction of a variable in order to reinforce/increase the frequency of a desired behavior. Venkman is actually engaging in Positive Punishment, the addition of a variable/stimulus (in this case the electric shock) designed to decrease the frequency of a behavior (wrong answers). In Behavioral Psychology, Negative and Positive do not refer to traditional ideas of good or bad but rather the addition or subtraction of a variable in order to enhance or discourage a given behavior.
(at around 1h 2 mins) Venkman tells Egon he has Dana "whacked up with 300cc" of Thorazine, a relaxant and anti-psychotic. "300 milligrams" would be more correct, as proper and vital practice is to describe dosage by weight, not volume. Besides, "300cc" is almost one-third of a liter of solution, certainly not doable given the circumstances but certainly fatal to Dana had it been so, if not diluted with sterile saline down from the standard 25mg/cc vials. That being said, 300mg Thorazine all at a single administration is exceedingly high even for severely disturbed patients. While it is likely an error, it could mean that a 300cc dose is necessary given the vague nature of demonic possession.
(at around 1h 8 mins) After the containment unit is shut down, Peck says that the Ghosbusters are 'in criminal violation of the Environmental Protection Act'. However, there is no such act, law, or guideline. There is a National Environmental Policy Act (NEPA), Clean Water Act (CWA), Clean Air Act (CAA), and many other environmental policies; The Environmental Protection Act is not one of them. Also, it is normal for a STATE agency representative to deal with any potential violations before requesting assistance from the EPA- the EPA could not possibly check up on every new potential hazardous business in the Region.
(at around 17 mins) When Dana gets out of the cab her groceries include a green leafy vegetable with a large white stem but when she gets to the hall it has become completely green lettuce. It changes to celery while she is talking to Louis. When she sets it on the counter it is still celery but in the next shot the item on the counter is lettuce. After the eggs start frying on the countertop it changes to lettuce and celery each pointing in opposite directions. When Venkman is checking out the apartment they are both pointing the same direction.
(at around 15 mins) When Egon, Spengler, and Venkman are walking to the property, Venkman is wearing a silver collar bar underneath his tie. However, when they are inside of the building, it is missing.
(at around 44 mins) After Dana and Venkman meet and set their date, Dana walks away with the violinist. As they walk, the violinist's violin case is alternately by his right side/tucked under his left arm between shots.
(at around 1h 21 mins) When Venkman comes out of the crumbled street, he has a small circular bandage on his right temple near the hairline, possibly an injury from a previous take. The next time we are able to see him from that angle is on the apartment building rooftop, and the bandage is missing.
(at around 50 secs) When we first see Alice the librarian, the books on the top shelf of her cart are all set spine-up, leaning back towards her. When the shot cuts to a wider angle, there's now a short stack in the middle of the shelf, with books on either side leaning against it.
(at around 12 mins) When Peter, Ray and Egon come out of the library, Egon's hair is noticeably different than it was while they were inside. When they go into their office to find they've been fired, it's back to how it was before.
When the Keymaster and the Gatekeeper ascend the stairs in Dana's apartment, the New York skyline is dark. When the Ghostbusters arrive in the remains of Dana's apartment shortly after, it is sunset. When the Ghostbusters climb the same stairs, it is suddenly night time again.
(at around 1h 19 mins) When the Ghostbusters first arrive at Dana's building before the final battle, two soldiers can be seen standing beside the Ecto-1 as the Ghostbusters walk by. When it cuts to a wider shot of the Ghostbusters and the Ecto-1, the soldiers are no longer there.
When the Ghostbusters team victoriously exits the hotel at the end after defeating Gozer, Dana and Louis both have marshmallow smeared in their hair, which did not exist in the earlier scene where they were pulled out of the corpses of the Terror Dogs. Also, being inside the Terror Dogs at the time of the destruction of the Marshmallow Man, they wouldn't have been covered in ANY marshmallow cream, since they are shown later being fully, physically inside the Terror Dogs.
(at around 1h 18 mins) When the Ghostbusters leave City Hall with the police escort, the red light on the top of the Ghostbuster vehicle is facing down and not visible to the front. In the next shot of the caravan, the lights on the Ghostbuster vehicle aren't on and the trailing police car's emergency lights are also off. When they pull up in the crowd, all the lights are on, including the red light facing up in the Ghostbuster vehicle. In the next long shot of the street when they are preparing to walk in the building, the Ghostbuster's and trailing police car's lights are back off. The red light on the Ghostbuster vehicle is facing down again.
(at around 1h 30 mins) When the Marshmallow Man is walking down the street (seen from the Ghost Busters' perspective, before the tiny hydrant explodes) the cables used to maneuver the character's face can be seen by his right foot.
(at around 1h 27 mins) When the Ghostbusters get hit by Gozer's finger lightning, as they are shot back you can see the stunt cable used to pull the Ghostbusters through the air moving out of frame in the upper left side.
(at around 1h 20 mins) Dana's building is located at Central Park, Manhattan. The police car in front of the building is from the 41st Precinct, which is located in the South Bronx on Simpson Street. This car would not be in that area.
(at around 40 mins) During the "montage" there is a shot of the guys carrying their loaded traps out of a building and crossing the street. Just before the next clip comes in, the shot reverses and runs backwards for a few frames.
(at around 46 mins) Dr. Peter Venkman claims that he has doctorates in psychology and parapsychology. Later in the movie (at around 1h 2 mins), he says that he sedated Dana Barrett/Zuul with Thorazine. Doctors of psychology, or parapsychology for that matter, are not MD's and so are not authorized to prescribe or administer drugs, especially a controlled substance such as Thorazine. However, someone as clearly immoral as Venkman would do so regardless of his credentials.
(at around 43 mins) Venkman says that Gozer was worshiped by the Hittites, Babylonians, and Sumerians in 6000 BC, which is long before any of those countries are generally accepted as having existed. The Sumerians first come into history around 4000 BC, the two Babylonian Empires lasted 1900 to 1600 BC and 626 to 539 BC, and the Hittite empire lasted 1600 to 717 BC. However, 4000 BC is only the earliest date *known* regarding the Sumerians, as no history was recorded before then, so they could have been around for millennia earlier. Those other groups existed in the same general region and grew out of earlier cultures, so there could be, in the context of the movie, a set of Gozer cults in 6000 BC in the cultures that the Hittites and Babylonians came from. (A simpler explanation, of course, is that Venkman is an idiot with no idea of what he's talking about, which is repeatedly shown to be the case throughout the movie.)
(at around 29 mins) The Ecto-1 has blue lights. In most states, only a government vehicle like police, fire, or ambulance would be allowed to use blue flashing lights on a vehicle. But the State of New York only uses red lights for emergency vehicles, and blue lights are never used on government vehicles.
(at around 1h 4 mins) When Winston and Ray are in the car talking about the Bible verse, Winston is in the driver's seat. When they pull up to the HQ after the explosion, Ray gets out of the driver's seat. (They may have stopped and switched seats between the scenes.)
(at around 50 mins) When Dana enters her apartment after Louis cajoles her to bring her date to his party (and locks himself out again), her obviously touch tone phone rings like an old rotary. However in the 1980s touch tone phones existed that had an actual bell in them and could emulate the tone of an old rotary phone.
Based on editing and dialogue, Ray buys the Ecto-1 car earlier the same day as the Sedgewick job. Given Ray's list of repairs the car needs and its initial appearance, it would take more than one day to get Ecto-1 to the painted-and-equipped state seen at the Sedgewick that night.
(at around 42 mins) The scene where Venkman meets Dana after her recital and arranges their date is cut between two scenes where Winston is instantly employed and hurriedly trained. In the other two scenes, all characters are wearing the same clothes, implying they occurred at the same time. However, Venkman is present in all three scenes and could not travel between the two locations in such a short amount of time. Also, during the scene with Dana, his uniform is clean, and he's wearing an orange shirt.
(at around 1h 20 mins) When the Ghost Busters are about to enter the building and the ground begins to break apart, you can see that the pieces of ground are not all solid. What appears to be a brown colored sheet billows out as one piece slopes down.
(at around 1h 19 mins) When the gang is about to enter Dana's building, an over-enthusiastic extra with ginger hair in an '80s cut can be seen in two different crowds that are supposed to be facing each other.
(at around 37 mins) In versions before the digitally remastered release, light can be seen reflecting off the camera lens when Venkman stops everybody so he can try to pull the tablecloth out from under the dishes.
(at around 39 mins) The USA Today cover, dated Oct. 8, 1984 lists an obituary for The Thin Man actor William Powell, who actually died on March 5, 1984. The designer of the faux covers, Michael McWillie, probably used the actual March 6th USA Today cover as the basis for his mock-up. (The text on the cover is only readable on the high-definition Blu-Ray version of the film.)
(at around 1h 30 mins) In a ground level shot of Mr. Stay Puft as he approaches Dana's apartment house, the lower section of the building shakes from the ground vibrations, but the upper sections do not.
(at around 1h 18 mins) The shot of the clouds gathering at Dana's building is a reuse of an earlier establishing shot (at around 16 mins). Note the people on the lawn on the right-hand side of the screen.
When Dana has been transformed into the GateKeeper, we see the balcony & outer portion of her apartment explode apart. The film flashes to the Ghostbusters and other scenes, which appear to take a long time. Yet in the next scene, the firemen and other personnel are only just getting to the apartment building?! There is also no indication that they ever tried to open the apartment door to see if anyone was hurt.
(at around 16 mins) When we first see Dana Barrett (getting out of a taxi), there is a shot of the avenue below her apartment from the roof, just before she steps out of the cab. On the side of the roof there is the head of a gargoyle with protruding sharp teeth - and "through" the teeth we can see the yellow traffic lines separating the lanes on the avenue below, showing the compositing used to achieve the shot.
(at around 1h 9 mins) When all the ghosts are escaping across downtown Manhattan, several ghost trails are not fully animated and abruptly cut off at the bottom right of the screen [Widescreen version only]
In the beginning of the movie with the library ghost. After the three of them find the ghost and talk among each other trying to figure out what to do, There's a shot with the guys on the left back side of the screen and the ghost reading on the right side of the screen, it's flipping through pages in a book, there are rectangles cut out of the pages in the book for wires and such to move the pages.
The goof items below may give away important plot points.
When the "marshmallow cream" falls from the top of the building onto Walter Peck, the splash is large enough to cover the rear driver's side corner of the Ecto-1. During the end credits, when the Ecto-1 is driving away, the same rear driver's side corner is clear of "marshmallow cream."
Prior to the final battle, the sky clouds over and darkens when the Ghostbusters prepare to enter Dana's building. Following the explosion, the sky clears to reveal stars. As they exit the building, it's sunny again.
(at around 1h 30 mins) When Peck gets doused with marshmallow, a nearby chunk of stone/concrete debris is easily moved several inches by the force of the goo. The debris is clearly made of a lightweight material, because the force needed to move actual stone or concrete as shown would likely not have left Peck standing.
(at around 39 mins) The photo of the Ghostbusters in the newspaper under the "Chinatown Spook" headline during the montage is clearly lifted from the "cross the streams" sequence later in the movie. (Compare the poses, positions and expressions.)
In the initial explosion from crossing the steams, as Peter says "Let's get outta here," the orange coloring of the flash stops at the pillars on either side of the doorway the men are standing in. Freeze-frames reveal the scene has been tinted between the pillars only. It's particularly obvious on the floor fog.