Other mistake: At the very beginning, when K disintegrates the alien Mikey, an MIB cover-up team arrives on the scene and approaches K at a distance of about ten meters (roughly 30 feet) ; whereupon K instructs them: "Give me a splay burn around the perimeter with holes at forty, sixty and eighty meters from right here! Thank you!" The team members disperse a scant few steps and use their flamethrowers and extinguishers on the cacti and undergrowth in the immediate area for five seconds. However, the distances K describes (forty, sixty, and eighty meters) would require the team laboriously dispersing hundreds of feet into the desert. But five seconds later, they're still only about 30 feet away from K when he says, "That's good! Thank you!" (00:07:55)
Other mistake: The first time the neuraliser is used it shows hours, weeks and years. But at the end of the film the lead character tells J to remember that it's "days, months, years." (00:08:06 - 01:24:52)
Suggested correction: Perhaps there are different models of neuralyzers.
I don't think arguing "perhaps such-and-such" is necessarily strong enough of a reason to correct a mistake. Nothing in the movie indicates they are different models, so it's probably best to assume they're the same.
Other mistake: When the two men are in the diner before they get killed by Edgar the bug, the subtitle reads, "Sure. I ordered you some Pirogi". The correct spelling is Pierogi. (00:42:00)
Other mistake: There is a mistake in the French subtitle translation. In the diner when the cook asks Edgar the Bug, "where's Ivan?" Edgar responds, "[I] gave him a break". The translator writing the subtitles must have thought he was saying "GIVE him a break" because the subtitle reads, "laisse-le tranquille" which means, "leave him alone". (00:42:10)
Other mistake: Soon after Jay pushes the little red button on the Ford POS, Kay inserts an eight track cassette. If you look at the eight track player, you can read "Select". The car is upside down at this point, but the word "Select" on the player, as well as the title of the cassette, "Elvis 'Promised Land'" are both right-side up. This means that, if the car were right-side up, the text would be upside down, and, in turn, the entire cassette player would be upside down. It is clear that this mistake was made by not paying attention to the orientation of the car as the scene was shot. It is also clear that the shot is done with the camera right-side up since Kay is in the driver's seat, which, right-side up, would be on the left, but since the car is upside down, he's on the right, which is seen when he inserts the tape. (01:14:20)
Other mistake: In the final scene outside the MIB headquarters, Kay opens the neuralizer and we see it open, but there is no sound. Later when Kay tells Jay that he hasn't been training a partner but a replacement, we hear the sound of the neuralizer opening and Kay tells Jay how to operate it. (01:27:45)
Other mistake: When K is searching for his wife on the computer, the zoom in highlight boxes don't match the videos.
Other mistake: When K is deleting all documents belonging to Edwards (later J), his passport says he was born in Indiana, but his birth certificate says he was born in Manhattan, New York.
Other mistake: Jensen (U.S. Army West Point Officer) addresses himself as a Second Lieutenant, but upon closer inspection of his rank (bars on his shoulders), they are Silver. Silver bars indicate a 1st Lieutenant, Gold indicates a 2nd.
Other mistake: After Mikey is gone, the guard comes down the embankment. As he does, the background "sky" now seems to have a long multi-story building outlined in it.
