The signs in the windows of the Russian restaurant change when shown from the inside.
When Kay shoots Jeebs in the head in the jewelry store, the resultant blast sends goop flying everywhere, yet in the next scene, the counter and wall behind Jeebs is completely clean.
When Rosenberg leaves his shop, Edgar's "Zap'Em" truck is
visible, reflected in the window. It is parked. The next shot of the street shows Edgar drive by and park in front of Rosenberg's shop.
The address on the back of the MiB business card goes from being below the logo to above it.
The license plate on the LTD changes from centered to the right-hand side during the film.
When looking at the star chart of Orion's Belt, Alnitak can be seen labelled as the middle star. From the northern hemisphere, Alnitak is the leftmost of the three stars of the belt (Alnilam is the middle star, Mintaka is the right hand star).
Kay says the MIB agency fund themselves through "a few patents", one of them being the microwave oven. However the microwave oven was invented in 1946 and is sold commercially since 1955 - before MIB even existed as an agency - making it impossible for them to patent it. Raytheon, established in 1922, owns the patent.
As Zed explains Orion's Belt to Jay at HQ, he rotates the constellation Orion vertically on a screen display and zooms in, showing the Belt's stars (Alnitak, Alnilam and Mintaka) to be in a roughly straight line and of equal brightness. In reality such an "overhead" projection of the Belt would show a long triangle with a very narrow base (Alnilam is about twice as far from Earth as the other two stars), with Mintaka on the right nine times brighter than Alnitak on the left.
Jay and Kay exit the morgue at night and go directly back to MIB headquarters. Jay goes to his computer and scans for his lost love in Cape Cod, which is in the same time zone as NY. When the image is located, it appears to be daylight when it should be in the evening.
When Kay is looking at his lost girlfriend via satellite, the view is
horizontal, as though shot from the ground, rather than "top down", as though shot from space.
When riding in the tunnel, Jay puts on an 8-track and listens to Elvis. Jay quips, "You do know Elvis is dead?" to which Kay replies, "No he isn't, he just went home," implying he is an alien. Earlier Kay reveals the aliens first made contact in 1961 - five years after Elvis Presley made his breakthrough performance on The Ed Sullivan Show (1948). However, 1961 is only when they made contact, not necessarily when they first landed.
In the opening scene, which is set in Arizona (saguaro cacti are only found in the Sonora Desert), we see New York license plates on the cars. However, it is possible that the MIB drove from New York to one of those states as the guy was bringing immigrants over the border.
In the tunnel, Jay falls upside down and appears to have a Caucasian leg. However, the behind-the-scenes featurette shows that Will Smith performed this scene without a stunt double, so this must be a trick of the light.
In the scene where Kay says, "You should have been here for the Zironion migration of 1968. I guess you were not even alive in 1968."
In the third movie we see a young Jay at the moon launch which took place in July 1969 and he is clearly older than 7 months old which would be his minimum age if not born in 1968.
However, Kay is mocking the youthfulness of his new partner.
In the third movie we see a young Jay at the moon launch which took place in July 1969 and he is clearly older than 7 months old which would be his minimum age if not born in 1968.
However, Kay is mocking the youthfulness of his new partner.
In the beginning of the movie, when Jay chases the alien into the building, he is initially seen running clockwise up the circular ramp, but after the scene cuts away and comes back, he is running counterclockwise. However, if you look carefully at the overhead shot when Jay starts running, you can see the first ramp he runs up left to right (clockwise) cuts back sharply and the floors then all move upward right to left (counterclockwise).
In the beginning of the film when Edwards is hanging off the back of a van chasing the guy, as the van turns into a street you can see nobody is in the driver seat. There is a person sitting in the passenger seat looking back through the window the whole time.
When the bug's spaceship crashes, although it's on fire (coming from sky behind the house) it has no effect on the shadow of the house.
A pedestrian speed-walks past Kay's car window when they are first in the LTD, indicating sped-up film.
In the tunnel when they're upside down, based on Kay's hand in relation to his seat (right hand holding tape and entering scene from right side places car upside down in shot), he places the Elvis Presley eight track tape into the player right side up, meaning the player is installed in the car upside down. The player also says "Eight track stereo" on front cassette door right side up to the shot, meaning upside down in the car. This is supposed to suggest that Kay regularly drives upside down in the tunnel and has the player oriented that way on purpose.
In the final scene, when Jay is fighting the big bug, he throws a rock and strikes the bug in the head. If you watch the rock closely, it disappears shortly after hitting the ground.
When the diner owner asks Edgar the bug "what happened to Ivan?" he replies, "(I) gave him a break". But the French subtitle reads, "Laisse le tranquille" which means "leave him alone" which could also be worded "GIVE (present tense) him a break" as an imperative.
When J chases the alien to the Guggenheim, the alien scales the wall up to the roof. J then shoots the window which breaks. The three shots he fired make no bullet holes on the wall opposite the glass door.
In the opening scene, Jay questions the immigrants individually. As he moves on from speaking to the third person in line, she looks directly into the camera until the camera angle changes.
When the aliens state the Earth has one hour and J is looking at the Queens pic in the fire ground and zed and K are talking in the back found you can see k's fingers moving above the keyboard but they are not touching the keyboard at all that he is standing in front of.
When Edwards moves the table during the "best of the best" test, the scraping sound begins before the table is moved.
When entering MIB headquarters, after spending the night deciding whether or not to join MIB, Edwards says to the security guard, "What's up hoss?" His lips never move.
Right before Kay unplugs the camera in the interrogation he says "Some night huh?" but his mouth does not match.
At 15 minutes when the farmer's wife adds sugar to Edgar the Bug's drink, the word 'Sony' and the serial number and bar code of the Sony prop house is seen on the bottom of the bowl.
When the alien jumps off backward from the roof of the Guggenheim Museum,
a safety cable can clearly be seen on his leg (just before the jump).
When the alien craft crashes, there is a shot of smoke rising, and off to the right side of the scene, men can be seen walking down the hill.
Partial reflection of the camera and its shadow can be seen when the camera follows the bank of lockers during Jay's initiation into the MIB.
As Jay is trying to follow Edgar after the gun fight outside the jewelry store, the pyrotechnic devices used for the cricket gun damage blasts are clearly visible for a few seconds before they burn out.
Kay and Jay stop an alien in a car (the alien with the pregnant wife) because the alien is fleeing Manhattan, the area to which his visa restricts him. The alien's car is pointed toward Manhattan.
As Jay chases the alien at the beginning of the movie, the chase starts at Grand Central Terminal. In the next shot, the alien is seen running downtown (the park is on his right) to get to the Guggenheim Museum. The Guggenheim is uptown from Grand Central, and so is Central Park.
When Redgick is stopped with his pregnant wife in New Jersey, the World's Fair-towers in Queens can be seen briefly in the background. Since the World's Fair took place in Queens, it's impossible to see them from New Jersey.
In the end where we see Manhattan's place in the galaxy, the camera zooms from a location near the center of the Milky Way. According to most scientists, earth is actually located on one of the galaxy's "arms".
When Agent Kay is looking up his lost love, he types "Truro", then zooms in on Cape Cod. As he closes in, he misses Truro on the map by about 50 miles' drive (the town/village he zooms to is actually closer to Forestdale or Wakeby). Also, the suburban grass lawn is atypical for Truro. Homes are mostly surrounded by pine needles, brush and dunes.
When the recruits are meeting to be tested an Army Lt. raises his hand and says he's an Army 2nd Lt. Except he has the silver bar of a 1st Lt.
As the camera pans into the morgue the corpse on the fridge tray has a neck pulse.
When Zed shows Jay the screen diagram of Orion's Belt at headquarters, the three stars are labeled in reverse of their true order, and Alnilam is misspelled as Alinlam.
Kay tells Jay, "500 years ago, everybody 'knew' the Earth was flat." The Earth's spherical nature was something that most scholars and all navigators were aware of as early as 400 BCE and has been common knowledge for the past 1000 years.
When Kay wipes the memories of the cops on the Mexican border, he says the neuralyzer will isolate the 'electronic' impulses in their brains, when actually it's 'electrical' impulses.