Continuity mistake: During the close up of Paul writing the word "Mark White" on the lid of the coffin, he is using his right hand. The shot then goes back to Paul, and he is writing with his left hand.
Continuity mistake: Near the start of the film when Paul has just taken the rope off his hands, he removes the gag from around his neck. It then cuts to a shot of him undoing his shirt. When the shot returns to the side view, the gag is back round his neck. (00:07:40)
Other mistake: When the man requesting money hangs up on him, a dial tone follows. Cell phones don't have dial tones.
Plot hole: Ryan Reynold's character is told by the military that his phone number is being suppressed. Later on, however, the HR guy from his company has no troubles to call him back.
Continuity mistake: When Paul calls his mom his forehead is covered in blood. A second later it's clean.
Continuity mistake: Paul writes "White" with a long line below the 'I'; however, later on, it appears written with a short line.
Continuity mistake: When Paul records the first video, the screen shows his hair over his forehead, in the rest of the shots his hairstyle is totally different.
