The movie is set in August 1999, however, a Euro note and an 'Elizabeth Fry' five pound note are pinned on the wall in Mick's hideout. Euros and Elizabeth Fry fivers did not come into circulation until 2002.
After the elderly man has stopped to help Kristy, but has been shot, Kristy is trying to put the keys into the car but is fumbling. At the same time, you can hear the audio of a car starting, but you can still see her fumbling with the keys in her hands.
When trying to start the car after leaving Wolf Creek, the engine wouldn't turn. Later he says that this is the coil pack. A faulty coil pack wouldn't stop the engine turning over. However, as Mick knows that none of the three backpackers know anything about engines, he can say whatever he likes is wrong, and they'll believe him.
After Mick shoots the good Samaritan character, he gets into his old muscle car and drives towards the car that Kristy is frantically trying to start. He then sits and revs his engine for a while before putting his foot down and chasing her. After shooting her, he loads her into his car alongside the good Samaritan, who he did not stop to load into the car.
The female Swedish backpacker's line is translated in the captions as "Come on, let's get him out of here", when she's actually saying "Hur i helvete kom han hit?", which in English translates into "How the hell did he get here?"
In shots from the back seat towards the driver's seat, both the tachometer and speedometer read zero - the car is in neutral and being pulled from the front while the characters are acting. The car is not running or being "driven" by the actors.
The goof items below may give away important plot points.
When Ben is wandering through the outback after his escape, there is a total solar eclipse. An approximately ten day old moon is then shown indicating a passing of about ten days. This is at odds with Ben's facial hair not visibly growing which would indicate a passing of much less time.
When Liz is making her escape from the shack where she is held by Mick, she looks out the window to see if it is safe to make her exit. We see that both right hand doors on the red Ford wagon are closed, but in all subsequent scenes, the doors are open.
After being rescued, Ben arrives in Kalbarri to be flown out by the Royal Flying Doctor Service. Kalbarri is over 2500 kilometres from Wolfe Creek. Even though Mick's lair is seemingly hours from the crater it would take over 2 days to drive to Kalbarri.
When Ben is wandering through the outback after his escape, there is a total solar eclipse. The film is set in 1999. The total solar eclipse of August 11 that year was not visible from any part of Australia.
When Mick shoots the elderly gentleman that was trying to rescue Kristy, you first hear the gunshot and then see the man get shot. The high powered rifle he is using shoots a bullet much faster than the speed of sound. Therefore, the man would have been hit prior to hearing the gunshot.