Continuity mistake: When the man is pinned to the wall by the Predator's spear there is a close-up shot of his feet showing a box beside his right foot. When it cuts to a shot from the side of the man the box is gone. (00:31:35)
Continuity mistake: As Quinn is sliding down the tunnel while trying to grab on to the ice with his icepick, he is sliding down with his feet first. Then he is suddenly sliding backwards with no time to have rotated. (00:32:35)
Continuity mistake: Close to the beginning, when the group is inside the pyramid below the sacrificial chamber, when the shot is from behind Lex and the others, note where the green light is, directly in the middle of the stairs. When it cuts to an overhead view, it's more to the left than the right. (00:36:50)
Continuity mistake: Below the sacrificial chamber when Lex says "This should be below the sacrificial chamber" you can see Lex and Sebastian walking towards the stairs, while Maxwell and Thomas are several feet behind them. When it cuts to a shot from above them they are all suddenly clustered together. (00:36:55)
Continuity mistake: When Lex and the others in the group reach the sarcophagus, Sebastian starts to turn one of the dials, the camera cuts to Weyland for his line, he has a flashlight in his right hand, yet in the following shot its no longer there. (00:37:50)
Continuity mistake: After Sebastian manages to open the sarcophagus containing the weapons, Miller sticks his head in to the sarcophagus and says "Any ideas what these are?" When it cuts his head is out of the sarcophagus. (00:39:00)
Continuity mistake: When the group are in the pyramid, just after they have discovered the weapons inside the sarcophagus, they begin to take them out. When Sebastian says, "Don't touch them", all the doors start to close, and Lex runs past a guy twice. (Slo-mo may be necessary.) (00:40:15)
Continuity mistake: In the scene with the sacrificial chamber, where the Alien eggs come up and start to open, the guy with the glasses (if someone can correct me on the name, please do), he shines the flashlight on the egg closest to him and focuses the beam tighter. As the camera angle shifts to a higher place, he does the same thing again. (00:41:05)
Continuity mistake: When the group walks along a passageway, the predators are watching from above, and in one shot the distance of the guy at the back of the group goes from about 8 feet, to almost right next to the others between shots. (00:44:55)
Continuity mistake: When the predators are watching the humans in a room, Weyland drops one of the guns from his backpack. Its position and distance on the floor from Weyland's boots changes between shots. (00:50:45)
Continuity mistake: When Weyland drops the Predator weapon we see from the Predator's view that Weyland grabs the weapon at the end of it. When it cuts Weyland's grip has moved further in on the weapon. (00:50:50)
Continuity mistake: When the predator lifts his spear before killing Max, the predator holds the spear by his chin level. When it cuts, the spear is almost over the predator's head. (00:51:40)
Continuity mistake: In the scene when the Predator is impaled on the Alien's tail, there is Predator blood all over the Alien's tail. When the Alien flings the Predator's body away, the Predator blood on the Alien's tail disappears. (00:52:30)
Continuity mistake: When the main Predator kills his first alien, he concludes the 'rite of passage' by burning himself on the forehead with alien acid. This should have left a circular mark on his forehead, but when we see him at the end of the movie, he only has the 'tau' symbol. (01:00:35 - 01:20:40)
Continuity mistake: When Alexa and Sebastian are walking down a passageway in the pyramid, after everyone else has been killed, they begin to hear aliens all around them and look around. When Alexa shines her torch at an alien, she is on Sebastian's right side, but in the next shot she is on his left side, and her small torch vanishes from her right hand. (01:05:10)
Continuity mistake: When Lex and the predator are going up the tunnel at the near the end of the movie. Lex has the alien head shield on her left arm. But when they are speeding up the tunnel, the shield is not on either arm. If you pause it, you can see the shield missing. When they emerge out of the tunnel it is back on her arm. (01:17:05)
Suggested correction: The shield didn't vanish. Lex removed it so that she could hold the sled with both hands. The shield is right between Lex and the predator. (1:26:58) When they emerge out of the tunnel, the shield is on her right arm.
Continuity mistake: In the scene where Lex is running in the abandoned whaler camp, the "shield" she is holding keeps changing hand between shots. (01:18:05)
Continuity mistake: When Lex and the Predator are running through the tunnel and neither of them has the spear that the Predator built for her. Then later spear is back. Then after the sled crashes, its gone again. For the remainder of the sequence, the Predator has it. (01:19:15 - 01:20:40)
Continuity mistake: At the end compare the shots taken from the top when the predator is lying dead over the snow; right after he dies and when the other predators are going to pick him up. His left arm changes position and his "rasta locks" are spread in a different pattern. (01:23:40)
Continuity mistake: Lex's initiation mark disappears in overhead shots.
