Revealing mistake: In the scene where Sam Neill has set the bomb to blow up the rescue ship, Laurence Fishburne comes running up to the sealed door of the Event Horizon whereupon it shakes back and forth like a stage door would.
Revealing mistake: During the opening scene, when the camera is starting to zoom in on the ship outside earth's atmosphere - the view of the crew inside zooms in quicker than the camera moving in to zoom into the cockpit.
Answer: As a representative of Hell, Dr. Weir was torturing Captain Miller with all sorts of horrific mental images. Miller cared very much for his crew, so Weir fabricated hellish visions of his crew. And the aft section of the ship didn't blow up, it was sucked into the Hell dimension.
Charles Austin Miller