20 Horror Movie Scenes That Make Absolutely No Sense

Plot: High school student Wendy Christensen (Mary Elizabeth Winstead) foresees a deadly rollercoaster disaster and manages to get several people off the ride before it crashes, but Death starts to come after those who were meant to die and cheated their fate.

Final Destination 3 might just be one of the most purely entertaining horror sequels of all time, but that certainly doesn't mean it's lacking in flaws. Namely, its rollercoaster crash disaster is a load of plot hole-ridden nonsense. 

Your writer is a die-hard rollercoaster enthusiast and can confirm that this movie gets pretty much everything wrong about rollercoasters. For example, rollercoaster restraints would never open like that when the ride is in motion. Even if hydraulic pressure is removed, there are multiple fail-safes, and a looping coaster of this model would normally have a seatbelt attached to its shoulder harness anyhow.

Then again, many Final Destination scenes are full of factual errors - the real confusion involves what sets the crash off. 

Frankie Cheeks (Sam Easton), the movie's douchebag, sneaks a video camera on board and drops it while upside-down. The train runs over the camera, and this sets the disaster off. However, Frankie is one of the people who leaves, and he takes his camera with him... and the rollercoaster then crashes in the same way it did in Wendy's premonition. What gives?