Continuity mistake: In the beginning when the man is running through the whaling station the two upper buttons on his shirt are unbuttoned. But when he falls on his back as the Predator is approaching him his shirt is entirely buttoned (Extended version only). (00:01:20)
Continuity mistake: In the beginning when the man realizes the Predator is in the same room, he falls to the ground and backs up against an oven. You can see several dippers behind his back, but only three dippers on his right side. When it cuts to a close-up there are five dippers. (Extended version only). (00:01:25)
Continuity mistake: In the beginning, when the man notices the "Unidentified Heat Signature" warning on the screen, he removes his arm from the table twice in separate shots. (00:03:05)
Factual error: Lex reaches the top of Lho La Ice Fall (Nepal) to find Max there standing in front of an Eurocopter AS350 helicopter. The problem is that this helicopter has a service ceiling of about 15,000 ft., and Lho La Ice Fall is at almost 20,000 ft. This is far beyond the capabilities of the helicopter's performance. (00:03:18)
Continuity mistake: Early in the movie the female protagonist "Lex" Woods is climbing an ice waterfall. The scene shown from a distance reveals a steep ascent above the ice, but in the next scene, she reaches a large area flat enough for a helicopter to land upon. (00:03:40)
Continuity mistake: When Sebastian starts to crawl back out of the hole after discovering the Pepsi-cola cap, the guy with the camera is holding the camera with his right hand, but in the following shot he is holding it with both hands. (00:03:50)
Continuity mistake: In the beginning when Lex answers the phone, her earpiece and ear are visible. In the next shot both are covered by her cap. (00:03:55)
Continuity mistake: When Lex comes climbing over the edge she rams one of her icepicks in the ground. Two shots later she has suddenly rammed her other icepick in the ground as well. We would have noticed if she did so. (00:04:25)
Continuity mistake: In the beginning when Sebastian is uncovering the tunnel he says "We must be right on top of it", you can see he rests his right arm over the edge of the bricks. When it cuts from inside the tunnel his arm no longer over the bricks. (00:04:45)
Continuity mistake: When Sebastian is checking the sand inside the tunnel, right before he finds the Pepsi Cola cap, you can see a close-up of his wrist and there is no sign of his watch. When it cuts his watch is visible. (00:05:00)
Continuity mistake: When Sebastian comes out of the hole to reveal the video camera he found, his red t-shirt has no mud/dirt on the front, but in the following shot when Sebastian is walking to the tent, there is a rather large long streak of mud/dirt on his t-shirt. (00:05:15)
Continuity mistake: When Sebastian has picked up the Pepsi Cola cap and about to uncover it, as Thomas is filming him, we can see his sleeve on his right arm is pulled up. When it cuts to a view through Thomas' camera his sleeve is further down his wrist. (00:05:15)
Continuity mistake: When Sebastian says "Thomas, the burial chamber is here. We're gonna find it." you can see a man with a blue shirt and a man with an orange shirt walking in the background. When it cuts the same men are walking but now several people have suddenly appeared behind them. (00:05:30)
Continuity mistake: When Lex is on her way to meet Weyland, Miller asks her to take a picture. When she first takes the camera, she puts her fingers on top, ready to take the picture, then she does it again. (00:06:25)
Visible crew/equipment: During the briefing Weyland says "But it's not on the ice, it's two thousand feet below it" it cuts to a shot behind Maxwell with an overview shot of the crew. If you look behind Maxwell you can see the tip of a head moving into picture. In the previous shot we could see no one was standing behind Maxwell, and it couldn't be Sebastian cause he went back to his seat. (00:07:55)
Continuity mistake: When Sebastian says that the experts are right he gets up and says "All of them" you can see his hands are down. When it cuts to Lex saying "Meaning what exactly? Sebastian has his left hand by his waist. (00:09:05)
Continuity mistake: When Lex is in Weyland's office on the ship, in one shot her arms are crossed, in the following shot, her hands are on the table, then back to crossed. (00:11:45)
Factual error: When arriving in Antarctica, there is dialogue about the full moon (la luna di cacciatore, etc...) There is no full moon on 10/10/2004 in Antarctica. But it does look nice in the movie... (00:12:15)
Factual error: The expedition leader claims that Bouvet Island is not under any national control, because of the Antarctic Treaty. However, because of its remoteness from the continent of Antarctica, Bouvet Island is actually not included in this treaty and Norway has full ownership of this island. (00:12:35)
Continuity mistake: When Lex Miller and Sebastian are talking at the side of the ship at the beginning, Miller says "Ii wish you'd consider coming with us ", it cuts to a shot from the side/back, she is looking either in Sebastian's direction or out to sea, yet in the following shot she is looking at Miller's face. (00:12:50)
Answer: When they emerged from the underground pyramid unscathed, the Predators assumed they were not infected. Any Predator, young or old, would have been taught to self destruct rather than be caught or killed. As seen in the previous movies. Lex was given the mark of a warrior, they assumed she was taught their code of honor.