Character mistake: At the beginning of the movie you can read the rules of the premises, in particular rule number 3 says; "No guns or any type of weapon permitted through the gates." However, the Wolf King's cronies dump their guns before the gate even when they were never supposed to be able to come in (so does Burke at the beginning, but he was trying to be admitted in). (00:07:15)
Continuity mistake: Nice draws a line in the asphalt of the secret passage (cool idea, although there's no way that the bad guys can actually see that especially at a distance!). In the first overhead shot, there's a gap in the line. When the line is shown again next with the first baddie croaking before it, the line has already changed. (01:15:45)
Continuity mistake: When Bautista confronts the thugs still to the other side of the gate saying "Visiting hours are NEVER!", Crosby is holding two consecutive horizontal bars in one shot, two with one bar apart in the next. (01:15:30)
Continuity mistake: Nice's hands invert position (left up, right up) when she is hugging/supporting Waikiki after he jammed the printer. A moment later she supports him with her left hand on his bicep, but it is gone in the reverse shot. (01:12:25)
Plot hole: Waikiki is not supposed to know who 'Niagara' is and most importantly, he is supposed to think that the Wolfking and his men are there for him and Honolulu. Yet the moment the Nurse mentions that Nice is "with Niagara", his reaction is as if he always knew the Wolf King is a patient. (01:10:00)
Factual error: Sherman prints a gun through the hospital's 3D printer. We see the gun, the cylinder, and 6 bullets. But if bullets are printed too, they still would need to contain the gunpowder, and the 3D printer construct shown there looks made out of a single kind of material, plain looking, surely not the product of a wonder machine that'd be able to recreate the complex chemistry required to make working bullets it was not even designed to do - in fact they look like suppositories, with no division at all between primer, casing, etc.
Other mistake: In the close-up of the gun freshly printed, there's a bunch of molten plastic by the gun cylinder and the grip. Waikiki retrieves it right away, bare handed, and the bed is completely clean too. (01:03:25)
Revealing mistake: Gone past Waikiki who tells him he knows about the cop, Everest wheels her to the secret door. Batista to open it touches the leftmost corner of the slat. In previous close-ups, the button was at much greater distance from the wall, surely not just an inch. He's pushing no button, just pretends to. (00:56:30)
Continuity mistake: The Nurse fixed the policewoman, and they had a chat. When she leaves saying she has to prep for Niagara and that "Everest will walk you through the aftercare", Batista crosses the arms he had already crossed in the previous shot. (00:45:15)
Continuity mistake: The Nurse asks Everest to pass her the microwave scalpel. During the scene, when she daydreams about her son's death, the earplug changes position and gets on her lapel during a cut. (00:40:00)
Continuity mistake: Nice walks away from the bar after she told Waikiki to run away. There's a close-up of Sterling K. Brown looking at the pen while the bottle of bourbon is in the foreground; the bottle is fuller than it is in the rest of the scene, where just barely the bottom is left. (00:39:20)
Continuity mistake: When Nice opens the pen-shaped safe, she holds it by the very bottom as it unlocks and extends, but her hand is back in a position next to the rim in the next shot. (00:38:05)
Continuity mistake: When the Wolf King's crony "double taps" the cops that Batista roughed up, the footage shows a strong projected light that was nowhere to be seen in the alley - even assuming the footage heightens the luminosity, it is not even consistent with how the footage from that security camera looked earlier. (00:33:55)
Continuity mistake: Batista knocks out of the three cops; the one that is lying further down the street is lying down at distance from the wall and oblique to the street's direction. In the overhead shot when the two staffers get back to the hotel, that cop is tucked in close to the wall. (00:32:55)
Continuity mistake: The police shoots one of the kids who were robbing the Nurse. The body is lying on the sidewalk when she says "No, no, I can..." to them holding her at gunpoint, but when Batista kicks the cops around, the body shifted further to the middle of the road - where it should have been to begin with. (00:32:50)
Continuity mistake: The Nurse and Everest chat in her room watching from security cameras both the Wolf King sealing the doors and the cop showing up at the other entrance. Throughout the scene, they chat with no room for significant breaks, and yet the time shown goes from 00:16 to 02:30, over 2 minutes in less than a minute of a scene (the time is not significant for the plot and it's a rather small detail in the HUD). It happens again later, after the scene with the three guests interacting over the cup of coffee; the timer jumps from 02:06 to 02:50 in the blink of an eye. (00:25:20)
Continuity mistake: Nice responds in cool fashion to Acapulco that her superiority is "not an act." She has her open hand on her hip. He gets up and Sofia Boutella's hand is positioned differently, with just two fingers in position. (00:23:30)
Continuity mistake: The Nurse just told Waikiki about his brother's addiction. She receives a call when she is outside the room. In close-up she is holding the tablet with just her right hand, lowering the left. Next shot and she is holding it with both hands. (00:20:10)
Continuity mistake: When Batista clotheslines Kenneth Choi out of the door, Jodie Foster has her hand on her chest at first, but in the alternate angle her arm is down her side. (00:09:15)
Continuity mistake: The Nurse unlocks the door to let Sherman and Lev in; in close-up you see she is relatively close to the keypad, but in the wide angle she has to stretch her arms all the way to reach it and is leaning on it. (00:09:05)
