This tiny scene ruins the movie, IMHO. I have a personal edit which simply cuts out the scene where they discover that the camera ran for hours, and it vastly improves it.
One way of reading the film is as an epistemological exploration of modern society and how one character evolves their belief systems in the face of both ordinary and extraordinary events. I love the movie far more than the book because it doesn't neatly resolve the "truth" of what Ellie experiences, and it leaves the audience, minus this scene, in the same place as the protagonist.