Revealing mistake: When Eric Matthews is smashing his foot, he hits it the first time and it shows a close up. If you watch the small amount of blood when he hits it again they have used the same shot. (00:04:00)
Revealing mistake: When Cole's friend is being attacked by crows, Cole and his sister are driving. The car starts to skid and an above shot shows many skids marks on the road from previous takes.
Revealing mistake: Just as the bus begins to roll down the mountainside, cables are visible which were holding the bus in place. Most easily seen during the first complete rollover. (00:05:45)
Revealing mistake: The roller coaster used for the Devil's Flight is really the Corkscrew at Playland in Vancouver, where all three movies were filmed. If you look during the opening credits, you can see the name "Corkscrew" up in the lights above the coaster. After this, it says Devil's Flight during the rest of the roller coaster scenes.
Revealing mistake: When Robert Thorn and Keith Jennings are opening the graves, they are sitting and kneeling on the snow-covered ground. However, none of the snow clings to their clothing, and Roberts light trousers do not get any wet spots on them from the snow, revealing that the snow is fake.
Revealing mistake: In the scene where Rose shines the flashlight down into the mine shaft, the light from the flashlight can be seen reflecting off of it, as if the lava down in the shaft is just a picture (or on a green screen).
Revealing mistake: When Selene falls into the tunnels of Tanis's lair where the lycans are, you can see the pad she lands on. It's almost passed off as falling snow, but watch how as she lands the 'ground' squeezes like a pillow. This was pointed out in the director's commentary. (00:44:00)
Revealing mistake: As Bobby and Brenda are loading the bodies into the van, Lynn can be seen breathing.
Revealing mistake: After Raye has finished writing down the agent's names onto the piece of paper on the subway, the "dead" man next to him can be seen swallowing. (00:57:30)
Revealing mistake: In a scene where Fido is turned around, you can see a part of his head that is pink. However the rest of his body is grey.
Revealing mistake: When Vanessa comes out of the girls shower and walks to her locker, in the back shot you can quite clearly make out the strapless bra she is wearing under her towel. Also, when she lifts her arm up you can briefly see the black material under the towel.
Revealing mistake: When Zoe is getting killed she is spitting out blood from her mouth. Everything is ok with that, except she spits some of the blood on the camera right before she is thrown over the balcony.
Revealing mistake: Near the end of the movie, when Starla is flung about by Grant, in some shots it is obvious that Starla is replaced with a stunt double, as there is a noticeable hair change in some of these shots.
Revealing mistake: When everyone first gets off the bus outside the hotel, Williams shakes hands with Margaret. If you look at his wrist you can see his real skin, not the prosthetic which is supposed to go nearly up to his elbow. It can be seen a little better in the next shot as well.
Revealing mistake: After the accident, you see the car's gear is in park on the steering column.
Revealing mistake: They let us see the stunt double's face for the girl Steven Seagal is fighting in the ending Cathedral scene, and she looks nothing like the actress.
Revealing mistake: In the scene where the group of unlucky virgin sacrifices make it to the Minotaur's sleeping chamber and are banging on the door trying to get out, one of them is gored and lifted into the air. When this happens you can see the harness and wires (the cables are about 1/2 an inch thick and black, one either side of the body). In the same shot the clothing of the gored victim is bunched up over the cables also. (00:47:40)
Revealing mistake: When Phoebe is looking at herself in the mirror, she's trying to find out why she isn't attractive enough for roles. When she takes her bra off and inspects her breasts, it's painfully obvious that that is not her real torso, as her head kind of bobs around in a strange fashion, showing that her face/head was superimposed onto another woman's body.
Revealing mistake: When the American man throws a square concrete tile at the monster it reacts (moves its foot in pain) before the tile actually makes contact. (00:16:11)