Corrected entry: There's no way anyone could cut off their hand with a knife the way Wormtail did. The only way they could do it is if they slowly sawed it off. Even if he raised the knife and swung it hard, there's no way it would work, the bone is way too strong. But Wormtail didn't even do that, he just placed the knife on his hand and moved it down. You couldn't even cut hair like that.
Corrected entry: In the scene where Harry goes up to the Owlery to retrieve the message sent by Sirius, we see a dark-colored owl fly inside from the opposite window that Harry is standing next to. The owl lands on a square basin but on the far side from Harry, who then turns around noticing that the owl has just flown in holding a note in it's beak. The owl is now on the near side of the basin closest to Harry. (00:41:50)
Corrected entry: After the first task in the tournament, Harry's arm is in a sling. But in the second movie, Madam Pomfrey stated that she can "mend bones in a heartbeat."
Corrected entry: Just after Harry speaks to Sirius in the fireplace and Ron comes down, Ron leaves and Harry goes back to the fireplace. In the background you see Ron going up the stairs, he goes into the dormitory on the right, but this is the *Girls Dormitory*. When they all arrive in the Common Room in the first movie, Percy says, "Boys' dormitories is upstairs and down to your left. Girls' the same on your right. And also in the first film, we see Hermione go through the door on the right after they see Fluffy for the first time.
Corrected entry: When Wormtail slices his own flesh in order to revive Voldemort, he cuts off his wrist before the shot switches to Harry. Later on, as Wormtail approaches harry to receive his blood, his arm is missing from the elbow.
Corrected entry: When Harry is underwater in the bathroom, Myrtle touches the open egg, disturbing its bubbles. How could she have touched them if she's a ghost?
Corrected entry: When Harry is in the Owlery, an owl flies in through the window and lands on a post. When Harry takes the letter off it, it shows the window again, but the beams on it are arranged differently. (00:40:00)
Corrected entry: The "Expelliarmus" spell changes throughout the films. In some cases, it just pops the recipient's wand out of their hand (the way it is actually used in the books), it launches a sort of ball of blue energy at the victim sending them hurtling backwards and stunning them (as used against Snape in PoA and Krum in GoF and is not necessarily accurate), or in the case of Goblet of fire, a jet of red electricity from Harry when used against Voldemort. It works for the film and books conceptually, but isn't consistent.