Revealing mistake: After John and Nelson are led to their prison cell, Nelson walks to the toilet and starts complaining about how disgusting it is. When Nelson steps away from the toilet, he breaks down in tears and let's himself fall backwards against the 'stone' prison wall. The wall is seen moving, which reveals it's not a real stone wall, but made from a softer material, like wood or plastic. (00:25:15)
Visible crew/equipment: At the end of the movie you see the three friends in the car driving away, there is a sunset and on his face is a shadow of a camera.