I love the Harry Potter films. I have dear friends who worked on them. I was on the set during the filming of Order of the Phoenix. David Heyman even told me that they used the Lexicon "every day" while they created the films. So don't mistake what I'm about to say for anything but loving criticism.
The films are nothing more than very expensive fan fiction. They're made-up stories closely based on the Harry Potter books, created by people who are massive Harry Potter fans and who care very deeply about "getting it right," but who, for one reason or another, changed a lot of things. Sometimes they changed things for very good reasons. Sometimes, though, they seem to have changed things for no particular reason at all. I can't explain it, but there you go.
However, for a lot of people, the films are Harry Potter. They've never read the books, or barely read them anyway. As far as they're concerned, Dementors attacked Harry and Dudley in an underpass below a highway. Snape died in a boathouse. And Harry fought Voldemort in an extended, violent duel at the end of the Battle of Hogwarts, punctuated by clever bon mots and death-defying falls from high places.
But oh well. I really don't care. At least they're Potter fans! The more the merrier! Just do me a favor ... don't send me any more emails telling me that I screwed up on the Lexicon when I write that: Read More