Revealing mistake: In the hospital scene when the nurse is filling the tub for the patient in the room above the cowboy's, he leaves the water on. When the water starts to come out of the tub it is coming out many times faster than it is going in.
Factual error: Towards the end of the movie, there's a drum of liquid with the number 4 on it. Number 4 is only on solids, not liquid flammables.
Revealing mistake: "Death" sets up Hunt's demise by activating the pool's purge pump and running it at maximum (so powerful it can suck the internal organs out of a person). The purge pump runs for several minutes before Hunt drops his coin into the water and goes after it. Despite the purge pump running at maximum all that time there is no change whatsoever in the pool's water level.
Revealing mistake: When George and Nick are walking across the street from the hospital where the "guy in the cowboy hat" is recovering, you can see that there was a green screen being used. As they are walking across the street, they seem to be a different shade than the background and a couple seconds later, George is hit by the ambulance.
Continuity mistake: When Janet gets to the car wash, the sunroof is closed. Minutes later she is seen closing it.
Plot hole: Throughout the franchise we are taught that when someone intervenes in death's plan that person is skipped until it circles back around for another attempt. However in Janet's case she is skipped by intervention at the car wash but is killed at the movies before the pattern is complete had the last vision unfolded as normal.
Visible crew/equipment: In the hair salon if you look into the mirror on the left as the camera moves, you can see the camera in shot.
Continuity mistake: When the bird craps on Janet's windshield, it's at a certain level. When she arrives at the car wash, it's slightly higher up on her windshield.
Revealing mistake: In the first shot of the custom car shop, a nozzle can briefly be seen spraying showers of sparks (supposedly from welding).