8 Movie Mistakes Acknowledged As Canon

Wes Craven's Scream boasts one of the most unforgettable opening scenes to any horror movie ever, satire or no, with poor Casey Becker (Drew Barrymore) being tormented and brutally murdered by Ghostface.

The scene is brilliantly executed enough, even, that you probably didn't notice a mistake hiding in plain sight when Casey runs to lock the front door.

For a few seconds, the shadow of a large, long object is visible behind Casey, and given that there's nothing in the room with that shape, it's safe to assume we're looking at a piece of set equipment - a crane, most likely - a shadow of which has been inadvertently projected into the scene.

Scream 2 then opens with a delicious parody of this scene, where Heather Graham plays the Casey Becker role in the film-within-a-film "Stab."

The scene is played out in exaggerated fashion, though given that the aforementioned mistake had done the rounds online following the original Scream's release, Wes Craven decided to include it in the "remade" version too.

And so, when "Casey" is running away from Ghostface, she speeds out of a doorway with another strange shadow on it.

Though at first glance you might assume the shadow was being cast by the plant to the left, the shadow becomes thicker and darker as the camera closes in, suggesting that the source in this case is also film equipment of some kind.