Continuity mistake: When Major Ben Daimio is saying the line about putting Hellboy back in his cage, he's walking towards an elevator door mid sentence and looking at the door. The camera cuts to a different angle as he finishes this sentence and suddenly his head has turned 180° with him looking at Hellboy instantly between shots. (00:41:55)
Continuity mistake: Dr. Stone mentions there is an emergency exit below the landing pad. He then asks the pilot if there is a camera underneath. In this shot, the pilot has his eyes partly closed and his lips pursed together. It cuts to a close up of him and suddenly his expression is different, with his eyes wider open and his mouth open. (00:19:50)
Continuity mistake: The new Bosley goes for a hug after reporting Edgar's demise. You can see as the hug begins that the sunglasses are not in Elizabeth Banks ' left hand, but it's where they end up when she says that "hugs work." (00:27:50)
Continuity mistake: While in the pool room, Zoey falls off the wall onto a portion of floor that hasn't collapsed yet and loses consciousness. This area is next to the section of floor that collapsed first. Jason jumps down to help Zoey. As he is helping her up, and onto the wall, that section of floor collapses, forcing him to grab the wall to avoid falling 20-ish stories with the floor. As he looks down drop, the section of floor that fell first is amazingly back intact. (00:59:20)
Continuity mistake: When Sasha is jumping from the stairs at the end, she is wearing black tights, but before and after she is wearing different tights.
Continuity mistake: En route from the front door of Wayne's mansion to the table in the Batcave, the pile of pizza boxes in Alfred and then in Mike's hands continues to change in size and number: at first the pizza girl delivers 11 boxes, Mike slams on the table just 8, but he brought down the stairs twice that amount (without counting through freeze-frame the precise numbers, it's simply obvious at first glance that the pile is bigger in some shots and the pizzas themselves are pictured of inconsistent size).
Continuity mistake: Batman enters Lex Luthor's room at night while he's sleeping, and completely casts a shadow over Lex. This wakes Lex up and he sits up. Batman has not moved from his position, but now in the next shots he is no longer casting a shadow on Lex's bed or body. (00:24:47)
Continuity mistake: When Nicole is telling Stu that he might as well call his gym "Old Hag Bikes", he is looking at her and smiling. It cuts to a close up of him and suddenly he's looking slightly up and off to the side with a pondering face. (00:53:25)
Continuity mistake: After the wolves have killed the guy poorly sniping them at the old encampment location, Clair Hamilton glares at Larsen from her sitting position and moves towards him to ask more about what he just said about Father. During this sequence, Gina Carano's hat is burdened by a bit of snow or practically no snow at all, back and forth with no logic between cuts. (00:35:50)
Continuity mistake: When Lance is telling the guard at the start that he's going to throw his gun to the snowman behind them, the snowman that is there was not there in a previous shot and appeared from nothing.
Continuity mistake: When Zander holds out the going away card for Miles to sign, the card flips over within his hand between shots, note Zander's four fingers are on the card's front then the back. (00:05:35)
Continuity mistake: When Monster Zero is standing victorious over the Mexican city, a traffic light changes from red to yellow.
Continuity mistake: In the first movie, it is stated that the program was started in the '50s, but in this one it is stated that Gustave Eiffel was an MIB agent. He died in 1923.
Continuity mistake: When Ash and friends are entering the wharf, there are two people that change between shot. There is also a person who goes from having his right hand in his lap to having it scratching his head. (00:23:06)
Continuity mistake: At the beginning of the movie, the girl gets assaulted from the back: you see at first exactly from the shot from behind that the backpack she is carrying escapes her arms, but in the subsequent shot she is still holding it. (00:02:10)
Continuity mistake: Feng's "sex doll" Maria apparently moves herself further down on the bed. When Bruce is offering Feng stacks of $100 bills, Maria can be seen in the background with her head at the middle of and largely horizontal to the two pillows by the headboard. After Bruce leaves and Feng turns around waving the credit card, Maria is closer to the foot of the bed and her head is more toward the right of the screen. (00:27:44 - 00:28:36)
Continuity mistake: In the police station, a guard comes out of the toilet and fumbles with his zip, the shot goes to a man on white talking in his phone. When he comes out of his office the man is still fumbling with his zip again. (01:01:03)
Continuity mistake: In the prologue, the Nazis storm the Bresson residence. The elder Professor Bresson is sitting at his desk, back turned to them. There's an open fountain pen next to him, right by a paper sheet, but when Bresson answers rather defiantly to the bad guys, the paper sheet suddenly has disappeared. (00:02:15)
Continuity mistake: After the alien abduction, Emmet plans to lead a rescue mission and opens the gate asking "Who's coming with me?" During the sequence, the shadows change completely. At first he is not casting much of a shadow, then it reaches the metal doors, then it stops midway towards it. (00:20:55)
Continuity mistake: The amount of blood on 10-year-old Miguel's face and neck after his "jump in" is not consistent. Sometimes there is more (or less) blood on his cheeks and neck and sometimes it appears splattered compared to large areas diluted with blood. The intensity/color of the blood also changes - sometimes it is very red but other times it is paler. The cut on his left eyebrow apparently was not on the far left corner yet sometimes the blood started there; other times, the blood started almost to the middle of his eyebrow. Sometimes he has blood below his eyebrow. Despite all the blood on his face and neck (down to the sagging T-shirt), there is no blood on his white or light grey T-shirt. He also does not get any blood on his jacket. Miguel was repeatedly punched then kicked by several large, muscular adult gang members for 13 seconds (to become a member of the MS-13 gang) but is unrealistically able to get right up then go and pick up and carry his dog - with no limping or signs of pain. (00:29:15)