Revealing mistake: After being dropped by the troll in the girls' lavatory, Harry then scoots backwards on his backside and it is apparent that he is wearing knee pads under his pants. (01:11:40)
Revealing mistake: During the Quidditch game, none of the players have shadows on the ground. (01:16:20)
Revealing mistake: Just after Harry gets back on his broom, the Slytherine seeker chases the snitch and he passes towers of (in order) Gryffindor, Hufflepuff, Ravenclaw, Slytherine, Gryffindor and Hufflepuff, on his left (this means Hogwarts is also to his left), when Harry flies up beside him. However, next shot as Harry slams into him, they still fly in the same direction, and the school is now on their right. Mistake with the background plate. (01:22:00)
Revealing mistake: When Harry is walking in the library's restricted section, you see the shadow of the library pillars on the bookshelf. If the light was coming from his lantern, there would be no shadow - the light is obviously from a spotlight elsewhere. (01:25:20)
Revealing mistake: When Harry brings Ron to see the mirror of Erised, the green side of the invisibility cloak is seen when they are running to the mirror, near the door they entered from. (01:33:55)
Revealing mistake: Harry, Ron and Hermione are at Hagrid's hut asking him about the hooded man and the dragon egg. The background behind Hagrid, which is the hut, is really behind him, but when it cuts to Harry, Ron and Hermione it is very apparent that the kids were edited in with their background, which is the school. (01:50:45)
Revealing mistake: When Ron is hit by the Queen during the chess game, the stunt double is visible on the horse just a few moments before he falls. (01:59:00)
Revealing mistake: During the chess game the Queen attacks the Knight's horse that Ron sits upon. In this close-up just before the spear actually hits the side of the horse, the large hole, used to aid the stunt, is visible in the belly of the horse between the stirrups towards the hind legs. This hole is not in previous shots. (Visible in fullscreen DVD.) (02:05:10)
Revealing mistake: At the end of the film, when Harry is leaving on the Hogwarts Express, and the overhead shot shows the train pulling away from the station you can clearly see that Hagrid is of normal height, as the train roof is much taller than he is. (02:23:40)
Chosen answer: Voldemort is not on his head in Diagon Alley as explained in the books. He attaches himself to Quirrell when he learns that Quirrell was unsuccessful in getting the Philosopher's Stone from the vault, in attempt to keep an eye on him.
But in the movie when they met in Diagon Alley, Quirrel refused a handshake because it would kill him.
It's never explained in the movie that that is why he doesn't shake hands. In the books, hagrid says that Quirrel hasn't been right since he met a few vampires in the black forest.
Ssiscool ★