Audio problem: The FBI agent is in pursuit of a suspect in a hospital, once he enters the stairwell he draws his Glock handgun, and a click can be heard for a safety disengaging. Glocks are striker fired, they contain no external safeties that can be manipulated that would cause a sound. A sound can also be heard after the gun is already drawn from the holster, representing a holster draw sound. (00:22:22)
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)
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)
Factual error: This is set in 1966. The soldiers are all using the Aussie version of the M16 which was introduced in Vietnam by their military in 1967 with limited use and only became more widely used somewhat later.
Suggested correction: There's no such thing as an Aussie version of the M16, they were all made in the USA by Colt, or its contractors. I assume the poster means the M16A1, identifiable by the bolt assist lug on the right hand side and closed flash suppressor.
Other mistake: The opening (like most of the movie) does not make much sense, so you can pick your kind of mistake here; the special effects are cartoonishly bad throughout the big firework explosions. When John Abraham is knocked through a window by a rocket (which takes off with a 270° turn without even rising) to the face, he gets up unscathed and starts screaming for Junky and Chandu. The camera moves from them to him and he's running with the girl in the red costume in front of him (which was way behind, safely, when he crashed through the window, so already that is wrong), and then there's a wider shot. In that shot, you can tell that Adams is bumping into the same people as before and the distances between the extras are all wrong. (00:06:35)
Continuity mistake: When Nicolas Cage aka Frank Walsh first shoots a blow dart at Kevin Durand aka Richard Loffler he hits him in the left shoulder. Ten seconds later Kevin he pulls the dart out of his right shoulder. (01:23:15)
Continuity mistake: At the start of the film, a man is giving a tour of a building under reconstruction to some potential buyers. One shot, as he's telling them that this sits on a 14-acre lot, there are just 3 people as they walk through a doorway. The film jump cuts to a closer angle, and suddenly a 4th person appears in front of them from thin air. (00:02:34)
Continuity mistake: After Wesley has intimidated the snot bully, he comes back home and finds the police. Sitting at the table, his mom holds his arm and says "Wesley, Mr. Chambers asked you a question." Mary Elizabeth Winstead has her right arm on the table, close to her body. Change of angle and she is holding the coffee mug instead. (00:45:10)
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: When the guy leaves the motel, he only grabs his jacket, but when he's outside, he has a helmet in his hand. (01:14:55)
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)
Factual error: Towards the end of the movie when Superman and Henshaw are fighting on the Watch Tower in space, Lois hits the sun shades to lower them so that direct sunlight can hit Superman and power him up. This is out in space with no atmosphere to filter the sunlight. The reason the blockers were there was for this reason, to keep the harmful unfiltered sun light from hitting people on the ship through the windows. However, she is able to stand there in the direct light after it's done and kiss and hold Superman without being hurt or burned by the intense direct unfiltered sunlight or its radiation.