Revealing mistake: When Ami's chest is being drilled by the "drill-bra" at the end of the movie, you can see blood flowing from her chest, obviously because of the damage the drills are causing her. Yet, later, you can see absolutely no cuts or marks on her breasts or upper chest, where the drills were penetrating her skin. The skin is simply soaked with blood.
Factual error: In the scenes of the world, when they show the plane flying between destinations, the location of Dublin in Ireland should be at least 50 miles further north along the coastline, as Dublin is not on the south coast of Ireland.
Continuity mistake: When Captain Jack Wander is handcuffed to the stairs, in the first shot you can see that the handcuffs aren't all the way clasped. When you see him from a different angle, they are clasped all the way.
Continuity mistake: When Durell and LeeJohn are in the diner just before robbing the church, the toast on the table is to Durell's right. Iin the next shot, it's in front of him, and in the next shot, it's back to his right. (00:28:45)
Other mistake: Bonnie the Rottweiler is referred to several times by her owner Brett as a female, yet it's a male dog.
Audio problem: Right after Det. Corelli finds the limerick in her apartment, she pulls out her gun and there is a distinct sound of what's supposed to be her cocking the hammer on her pistol. However, Det. Corelli (along with all the other cops in the movie) uses a Glock semi-auto pistol, which does not have an external hammer that can be "cocked." The sound is added artificially, likely for dramatic effect. (01:06:30)
Other mistake: It is crucial to the story that Peter is terrified of moths - but when he is led through the woods at knife point by Tracey, a large moth flies around both their heads for several seconds (lured by lights of the film crew) and he ignores it, being as it's an unplanned visitor. (00:42:30)
Factual error: If Billy/Jigsaw's facial muscles and tendons were "completely destroyed" as his doctor indicates, there is no way he would be able to speak normally, and especially not in his original voice.
Factual error: At the end of the film, Wyatt and McQuarry each take a briefcase containing $5 million dollars. $1 million dollars in $100 dollar bills (highest denomination in circulation) weighs approximately 22lbs = 110lbs for $5 million. $5 million in $100 dollar bills is also approximately 3445 cu. in. in volume. This would not likely fit in the cases they are carrying, and would not be as easy to carry as they are.
Continuity mistake: When Jessie and Carlos walk to the church ruins, a big bruise on his nose suddenly appears for a couple of seconds, only to disappear briefly after.
Visible crew/equipment: In the opening murder scene watch when the man is stood outside the connecting train car doors, there is a shot from behind, moving in on him, and if you look out of the left window you can see a set of yellow ladders. This is set equipment and the train obviously can't be moving. (00:02:20)
Continuity mistake: During the sex scene between Milo Ventimiglia and Lauren Lee Smith, in which the fat guy was found dead, three consecutive shots showed that Milo Ventimiglia has his shirt on on the first, then the shirt disappeared on the next, only to reappear on Milo Ventimiglia's body again in the third shot.
Continuity mistake: The car they pour petrol/gasoline over in the closeup shot is a 2007 Chrysler 300C Hemi with the big square-shaped grille. In the long shot where the car blows up, it is not the same car; the grille has changed shape and is more akin to an old Mercedes.
Suggested correction: The grille hasn't changed shape, it looks different because of the explosion damage.
Continuity mistake: In the scene where Larry The Cable Guy is eating a long dog while talking to Madeleine, he keeps biting down on the bun, yet the eaten part reappears. This happens twice during this scene.
Plot hole: Blackbird and Ritchie fake their deaths in order to lure Wayne and Carmen out of hiding. What was the point of pursuing Wayne and Carmen? The only reason they wanted the couple dead was to prevent them from testifying. The problem is .if Blackbird and Ritchie were "dead", the case would be CLOSED. Carmen and Wayne wouldn't be testifying anyway. So why go to the trouble of killing them? It makes no sense.
Revealing mistake: The raid took place at Xmas in 1951. In homage to this fact, the characters wear big coats and one of them even rubs his hands together and goes "Brrr." Yet the movie was filmed in the height of summer. Trees in the background of scenes in London are full of leaves, we never see any mist in exhaled breath and the lighting levels and shadows indicate a high, bright sun.
Continuity mistake: When the brothers are standing on the rocks on the beach, the clouds change back and forth behind Stephan.
Continuity mistake: When the boss retrieves the phone from the suitcase, the suitcase between shots if strongly lit all of a sudden. (00:45:20)
Continuity mistake: Mike Manador watches his girlfriend Gina drive away in a taxi. Behind him a truck can be seen coming down the street. Mike then steps out into street seconds later, but the truck has vanished. Next shot looks up the street and sure there is the taxi but no other vehicles, and you can see the entire street. (01:41:25)
Continuity mistake: When the mother puts the drawing from her daughter in her pocket she puts it in the left pocket of her jeans. When she takes it out later, she takes it from her right jean pocket.