Continuity mistake: Jeffrey begins giving J a quick crash course on how to use the Time Jump device on top of the building. Just before he says "When you're moving fast enough" he pats J on the back, receiving an angry look from J. Jeff then puts his arms down as J begins slowly moving forward. The camera then cuts to a closer shot as he begins that line, and suddenly Jeff's arm is back on J's back, and J's arms are in a different position. (00:34:25)
Other mistake: When J is falling from the Chrysler building, the soles of his CGI shoes are completely black, brand new and spotless, which is impossible unless he got up there flying or changed his shoes in mid-air. (00:36:00)
Revealing mistake: During the time jump, there are several points in which it is apparent that J has been animated. (00:36:05)
Continuity mistake: When J lands back in time, the people behind him walking inside the building are not continuous between shots. (00:37:05)
Continuity mistake: After the time jump has finished, J is shown lying two feet above the ground. The first shot shows J to be looking very shocked with his eyes wide open. Then in a close-up, his eyes are suddenly almost half closed looking exhausted, and his head is shifted to the side. Then in the next shot, he's suddenly back to having his eyes wide open, looking shocked. (00:37:10)
Factual error: When J arrives on top of the bird on the Chrysler Building in 1969, he looks around at the view. The North Tower of the World Trade Center (One WTC) should be in view. The construction of the North Tower began in the summer of 1968. In 1969, even though the very top was still under construction. The first tenant moved in. Even though One WTC wasn't officially finished until 1972, in July 1969, there should be a clear view of at least 3/4 of that tower. (00:37:20)
Continuity mistake: When J exits the Flatiron building in 1960 a woman walks right behind him, then the shot cuts to his POV of a group of hippies, then back to the previous shot of J and the woman obviously continues her walk. She should've been several meters ahead already. (00:38:30)
Other mistake: J exits the Flatiron building and a woman in a yellow dress starts walking behind him. He looks at the street ahead and the same woman is walking from right to left. (00:38:35)
Continuity mistake: When J steals the blue car keys, a nerdy looking guy with an orange and white striped shirt and glasses is walking towards the hotel. After J drives zooming through New York, the same guy is seen crossing the street walking the opposite way. (00:39:15)
Factual error: When Boris arrives at Coney Island, Cha Cha's Bar and Cafe on the right prominently displays a phone number with area code 718. Area code 718 was created in 1984, 15 years after the 1969 setting. In 1969, all of New York City was in the 212 area code. (00:39:30)
Factual error: In 1969 while Boris is riding his motorcycle on the boardwalk in Coney Island, he rides in front of Nathan's Famous. In 1969 the only Nathan's Famous was on Surf Avenue. It wasn't until approximately 35 years later, in the mid 2000s, that Nathan's opened a smaller satellite store physically on the boardwalk. (00:39:30)
Continuity mistake: When the 60's cops stop J by the billboard sign, he pulls over by the left end of the sign. In the close-up, the car is parked right by the middle of it. (00:40:20)
Continuity mistake: When the racist cops are frisking J, one pulls out J's gun and questions him about it. In the reverse angles, the cop is holding the gun over J's shoulder with almost all the handle in his hand. In the shots showing J's face, the cop is holding the handle so that some of it is sticking down, and it is in front of J's shoulder. (00:41:00)
Continuity mistake: When the cops are frisking J, the small cop on the left's left hand keeps changing position in every shot, with no logic whatsoever. (00:41:00)
Continuity mistake: After being pulled over by the racist cops, J insults them and they pull him out to frisk him. As they have him bent over the car, one of them pulls out his gun and says "what's this, a concealed weapon". In the shot from behind J turns his head to the left to look at the gun. It cuts to a view of J's face as he says "Hey, it's his grandmother's suit." J is instantly looking straight forward. (00:41:05)
Factual error: When J is driving to Coney Island and is stopped by the two police officers,the view of Coney Island in the background is wrong. You see the Wonder Wheel ferris wheel and to the right you see the Cyclone roller coaster. The only way you could see the Cyclone to the right of the ferris wheel would be if you were on the boardwalk, on the beach, or in the Atlantic Ocean. (The tall cylindrical ride between the coaster and wheel is verification that the roller coaster shown is the Cyclone.) In addition, in 1969 there were two other roller coasters - one of of which would've been seen in that view - the Tornado which would be to the right of the ferris wheel which means the proper view should be two roller coasters with the ferris wheel between them. (00:41:45)
Factual error: When J walks through Coney Island's Luna Park in 1969, the Tickler roller coaster can be seen in the background. However, it is a spinning Wild Mouse coaster, which wasn't introduced until 1997. (00:41:55)
Continuity mistake: When Boris is questioning Roman The Fabulist about where the Arcanan is, Roman has a cigarette in the corner of his mouth. When Boris takes off Roman's hat, the cigarette has moved to the center of his mouth. (00:42:05)
Continuity mistake: When Boris kills Roman the Fabulist, the spike he shot at his head is located to be just an inch or two above his eyebrows. When J finds the body a few moments later, the spike is suddenly much further up his head than it was a few moments ago. The spike has also shifted an inch to the left. (00:42:15)
Revealing mistake: At Coney Island, K zaps J's neck with a tazer and knocks him out. J is seen falling onto his back on the ground, where the background fades out to show time passage that he wakes up sitting in a chair in MiB head quarters. The effect was cool, but the way it was done reveals itself. J wakes up in a leaning back seated position looking up as his head is slumped back over the chair. It is obvious they used this part of the footage to show him lying flat on his back on the ground at Coney Island, only you can tell he is not lying flat on his back. (00:42:55)
Chosen answer: The gold saucer crashed in middle of the street was the ship Boris stole to get to earth. While they are in the restaurant Kay gets a call that tells him a ship was taken from lunar max and it was Boris who took it.