Continuity mistake: When J is digging through files to try and find out what happened between Boris and K, O comes in and talks to him for a moment. As she is leaving, shots of J shows he is leaning back in his seat. But when O is shown, the glass wall she is by shows his reflection, leaning forward and slouching. (00:22:20)
Continuity mistake: When K grabs the remote to lift the library wall, the remote is facing a 9 o'clock direction, but in the close-up it's facing a 6-7 o'clock. (00:23:20)
Continuity mistake: After the timeline is altered, J returns to MiB headquarters where he is met by Agent Double A in the elevator. After a brief monologue by Double A, J turns to him and says "Give me 5 feet, or I am gonna pluck you in your throat." He holds up his hand like he is going to flick Double A. In one shot, his wrist is bent up, but in the next shot, it's bent down. (00:26:20)
Continuity mistake: When J believes K is playing a joke on him, as O says "who is he to you?", she raises her finger. In the next shot, the position of her finger changes. (00:27:25)
Continuity mistake: In the Headquarters in the altered time line, when J is crying out that he and K spent 14 years of stakeouts, cowboy music, etc. A woman in the back swaps from standing by a screen to walking 20 feet to the right, between shots. (00:28:40)
Continuity mistake: In the scene where J and O are talking about the temporal rifts (just before they are alerted to the invasion of Earth) the ring on O's left hand keeps disappearing and reappearing. (00:29:45)
Continuity mistake: As J and O are talking about temporal rifts, after J states Boris was on Lunar-Max, O says "If Boris could figure out how to time jump, he could seriously change the course of history." In this shot, her left hand is raised and her fourth finger is shown to be placed on her thumb. Next shot, her finger and thumb are no longer touching and her finger is now pointing to the right. (00:30:30)
Continuity mistake: At the electronic store, when J arrives, the headphones on the counter keep changing position between shots. (00:31:35)
Continuity mistake: After J shows Jeffrey Price the news report of the Boglodites, Jeffrey asks J "What's the plan?" and J is then shown raising his shoulders and placing his gun back into his back pocket. In the next shot, you can see J begin to do raise his shoulders in the same fashion as he did in the previous shot a second time. (00:32:20)
Continuity mistake: When J shows Jeffrey the alien invasion on TV, the notebook on the counter swaps from open to closed, and then back to open between shots. (00:32:25)
Continuity mistake: When Jeffrey places the time-remote control on the counter it lays next to a notebook. In the close-up it's gone. (00:33:05)
Continuity mistake: When Jeff sets the box with the time device in it on the counter, he begins to open it with one hand on the side of the box, and the other hand on the front of the box. It cuts to a close up and suddenly his hands are both on the sides of the box. (00:33:05)
Continuity mistake: As J pops his head up on the tall building, there are windows immediately behind on his right and left and both are closed. The camera pulls up and back to show the scale of the building, then cuts back down to J. Now suddenly the window on his right side is open, and the lamp in the room is on. The window also changes from closed to open a few times in this scene. (00:33:25)
Continuity mistake: When Jeff is talking to J on the Flatiron, he is looking at J except for a brief shot where strangely he is suddenly facing left without having turned his head. Then a frame later, from another shot, he is back facing J. (00:33:50)
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)
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)
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)
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)
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)
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.