Continuity mistake: When King is fighting with Lazarus in the bar, Lazarus gets blood near his mouth like you get when getting hit in the face. But when they fight near the white door, the blood is gone. (01:13:00 - 01:18:00)
Factual error: During the opening credits. An LCD screen is shown with lat/long coordinates. The movie takes place in the Persian Gulf. The coordinates are in the vicinity of Oceanside, CA.
Revealing mistake: The El Camino that is going over the cliff, which has just been shot in the tailgate with a 50 caliber rifle, has no tailgate damage. Also at the same time stamp, when the El Camino is upside down, it is obvious there is no transmission or drive shaft in the car. They even show you this with a close-up. (00:46:20)
Character mistake: The professor identifies the "sea monsters" as plesiosaurs from the Pleistocene. Plesiosaurs became extinct at the end of the age of dinosaurs, nearly 60 million years before the Pleistocene. Of course, the Loch Ness Monster might be an exception.
Factual error: One of the women in the group picks up a piece of calcite (Iceland Spar variety). It is obviously calcite because of the very obvious rhombohedral cleavage and other visual indicators. The sample is later identified as ringwoodite. Ringwoodite is cubic with no reported cleavage. Even if it did exhibit cleavage, it would not be rhombodedral.
Visible crew/equipment: When Yu and his friends have finished dragging Yoko into the van, Yu jumps into the van and closes the door behind him. When he finishes closing the door, the reflection of the boom mic can be seen in the window. (02:44:50)