(at around 1h 26 mins) Near the end, when Mark throws a spear just before entering the helicopter, the spear flies sideways and into the ground, but it is then shown to impale someone yards away.
When the killer early in the film is hit by the truck, He is nowhere near the truck when he's suddenly struck. Also, he would have been thrown, not likely run over.
After the cannibals have stripped, raped and eaten Diana, amidst the close-ups of them chewing, there appear on the corpse, for no apparent reason, a pair of psychedelic colored panties, which after 2 shots, disappear again in the final wide shot.
When Mark kills a cannibal after watching them eat in their cave, it's dark outside, but once he runs away, it's daylight again. It's because the castration scene was edited into the movie.
When Mark is attacked in the water at the end of the movie, at least two cannibals were right behind him, but only one is shown in the following shot and the rest are shown farther away than they were.
A blow dart would not likely penetrate the lapel (double layers) of a blazer and a dress shirt.
At the police station, the US flag is hung the wrong way. When displayed vertically, the stars and stripes must be in the top left corner, as when displayed horizontally.
The airliner early in the movie read 'Pakistan International.' The word 'Airline(s) is missing.
The fire walking and the back-piercing/hanging are religious traditions from Bali, not Papua New Guinea.
At the cremation festival, there is a US flag flying. This would not happen in Papua Guinea. Also, the flag of over the altar is not that of Papua New Guinea.
Obvious stunt double when Butler is fighting Karan.
Obvious fake meat when woman's breast is cut off.
When cannibals head is decapitated, his head can be seen moving on the ground, revealing that the man is just buried in the sand with his head sticking out.
When Karan is shown decapitated, he is actually just buried.
When woman's leg is shown cut off and being eaten by cannibals, it's obviously just buried in the dirt.
On the cheque Shelia Morris gives to Mark, there are two glaring mistakes. She has not dated the cheque, and her signature has no 'S' at the end of her name.
When the cannibal is eating the woman's foot, her body is in the background of the shot showing her severed leg. The foot that is missing from the leg is the left one, but the cannibal is eating the right foot.
The prosthetic torso stabbed in the castration scene bears marks and protrusions (probably intended to represent scarification) that are not present on the body of the actor playing the victim, and just before the camera cuts away from the stabbing, the bottom edge of it can be seen above the actor's groin.
Although this movie is set in New Guinea, you can see several animals like Green Iguanas and Macaws that only live in South and Central America.
(at around 12 mins) Sheila arrives at New Guinea in a Pakistan International Airlines flight. Pakistan is thousands of miles away from New Guinea and has never had flights there. The ground crew and pilot who helps her meet Mark are also Pakistani.
No reason is ever given for the blow dart murders in the opening sequence. The detective's focus turns to finding Diana, and they are no further investigated nor mentioned again.
Explanation: Diana mentions that Jonas already had people in Canada who wronged him killed. What's more, it is shown that Jonas and his cult use poisoned blow dart's for killing, so those people who are killed are probably some failed converts to the cult too.
At Sheila's initiation, all of the extras have obviously been directed to look away from the camera at a fixed spot, but a girl removing a tray walks close in front and momentarily looks directly into it.
Even though she never has an opportunity to refresh it, Sheila's make up stays perfect and unsmudged throughout her time in the jungle.