Continuity mistake: When Julie free falls she is facing a 9 o'clock direction. When the shot changes she is now magically facing 6 o'clock.
Revealing mistake: When Peyton is making Paulie's mask, note the burnt right hand typing on the keyboard. It moves like a stop-motion object, revealing it's either a robotic hand or an animated effect.
Continuity mistake: After Peyton stops holding Louis' leg, he opens his hand and there is no visible damage despite having just had a huge nail pinned through it.
Continuity mistake: Peyton lets Louis fall, who dives head first. A shot later he flies horizontally.
Continuity mistake: When Peyton's hand gets pinned to the beam, it keeps changing positions in every shot.
Continuity mistake: While standing on the beam, Louis cries "I built it all!", and the gun in his right hand appears and disappears between shots.
Continuity mistake: When Louis takes Robert's mask out and reveals Peyton's burnt face, Peyton takes his left hand to his cheek. When the angle changes, his hand is lowered and he repeats the movement. In the following shots the position of his hand is inconsistent all the time.
Continuity mistake: During the helicopter scene, when Peyton is hanging onto the cable, in the close-ups he's simply grabbing it, but in the wide shots the cable is strapped around his body.
Revealing mistake: When Paulie is thrown out of the window he is replaced by an obvious stuntman: His bald cap is way lighter than his skin, as opposed to Paulie's whose skin colour is homogeneous.
Continuity mistake: While on the helicopter, Peyton smacks a goon's face, who turns away and shows a streak of blood on his mouth. When the angle changes his head position has changed and is now facing Peyton.
Continuity mistake: When Guzman runs into Smiley wearing several masks, Smiley knocks him out. On the floor, Guzman's head is facing straight-up. In the close-up, it's tilted sideways.
Revealing mistake: When Peyton's hands are about to be burnt, they are a replaced by a very obvious prop.
Suggested correction: I personally see nothing wrong with the effect. While it is indeed a stop-motion effect, it certainly doesn't look cheap, the animation of the skin burning and curling is pretty smooth, and nothing inherently gives it away outside of the fact you know they wouldn't actually burn up the actor's hands.
Continuity mistake: The wet coffee circle stain on the paper is above the word 'date'. When the angle changes and the stain is dry, the circle has moved several centimeters below and is now surrounding the word 'date'.
Deliberate mistake: When the movie begins, Durant's men are frisked by Eddie's, one of whom was tossing his nunchucku seconds before. Angle cuts to Durant's men's weapons falling on the floor, the nunchucku among them. This adds up for tension as to show how heavily armed and dangerous Durant is, but is absurd that Eddie's goon disposes of his own weapon in such a dangerous situation.
Other mistake: Just before the Strack helicopter which Durant is in hits the bridge, the letter and numbers painted on the side just forward of the cockpit door are backwards, like a mirror image.
Continuity mistake: Halfway through the film, Frances and Colin are in Colin's office. Colin has a glass of brandy in his hand, but when the phone rings, the glass is gone.
Continuity mistake: Look at the police officer in the helicopter towards the end of the movie. In one shot, the words "POLICE" across the helmet are reversed like a mirror image. In another shot the same police officer's helmet says "POLICE" in normal letters.
