Continuity mistake: When the killer (Jigsaw I suppose) is releasing Tom's children from being hung by their hands, right when they get down the rope holding them up disappears.
Scary Movie 4 (2006)
Plot summary
Directed by: David Zucker
Starring: Bill Pullman, Anna Faris, Regina Hall, Craig Bierko
Genres: Comedy
More mistakes in Scary Movie 4
Tom Ryan: I've never been a good parent. Just ask my son.
Cindy Campbell: I did. What exactly is an "Ass Clown"?
Tom Ryan: That's not important right now.
More questions & answers from Scary Movie 4
Answer: Ads are often made months before the final editing of any movie. Therefore, it's not unsual for something to be in an ad but not in the final movie (or to happen differently, or a different shot, or different music, etc.).
Myridon