Roller Coaster disaster how real one happened.
The premonition has Frankies camera causing the disaster. He got off the ride and so that didn't cause the real one. How did it happen because they never explain it in the book either.
shareThe hydraulics would have been getting weaker and weaker during the fight so it would have needed a camera to help cause it. That's how I took it, and it even got put into the FAQ. I like how the book draws attention to it by having Ian point out the flaw, almost like a awareness joke aimed at all the viewers who pointed it out themselves.
Note: In an old script, it is shown that one of the football players* had a camera of his own, so the explanation was going to be "Frankie's not the only one with a camera" from the look of things, so take it as you will.
* The original script had the offense of the KcKinley football team on the roller coaster as the reason Jason and Carrie didn't sit with their dates (Jason was quarterback, Carrie was team manager).