Continuity mistake: When the Weasleys give Harry the Marauders Map, Harry takes it from George with his left hand, yet in the next shot the map is in his right hand. (00:57:10)
Continuity mistake: As everyone watches Aunt Marge start to soar up into the air while in the yard, the position of the white lace tablecloth, which hangs off the table at this point and the things upon it, differ in the exterior shot looking in towards the dining room and the following interior shot of the table. (00:05:55)
Continuity mistake: When Potter is learning the Patronus charm, as he is facing the candle and is talking about his memory and saying "It's the happiest I've ever felt.". His hair has an extreme change in the next shot. (01:07:10)
Continuity mistake: As Potter is walking back to Trelawney with the ball, as he enters the room through the tight passage, you can see light is shining in. When it cuts to him entering the room the light is gone. (01:17:35)
Continuity mistake: After saying goodbye to Harry, Sirius climbs onto Buckbeak and Hermione hands the chain to Sirius. In the next shot Sirius holds the chain differently. (02:04:15)
Continuity mistake: When Ron and Hermione are arguing about Crookshanks in the Leaky Cauldron, Sirius does not move in the 'wanted' poster. That same poster is visible when Harry first enters with Tom, and Sirius doesn't move in that shot either. However, when the poster is the focus of the shot, Sirius does move in the magical poster.
Continuity mistake: When Malfoy shouts "Dementor. Dementor." all the kids turn around. Then we see Malfoy and some kids put their hoods on, and at the same time we can see Hermione turn back. When it cuts to Potter turning back we can briefly see Hermione turn back again. (00:31:45)
Continuity mistake: When Potter points his wand at Uncle Vernon you can see his index finger on the wand. When it cuts his index finger is pulled back. [Harry has obviously jerked backward when Uncle Vernon approaches him -- Vernon is obviously closer in the second shot -- and it would be a natural reflex to withdraw his finger as well.] (00:06:25)
Continuity mistake: In the beginning when Aunt Marge says, "The bitch and the pup" and Harry yells at her, Mrs. Dursley turns to look at Harry. When the shot changes, Mrs. Dursley is now facing the table, away from Harry. (00:04:00)
Continuity mistake: In the scene when Hermione punches Malfoy in the face, she holds her wand to his neck with her right hand. The shot changes to her turning away and then she punches him - both her hands appear in the shot and her wand is gone. In the next shot she mysteriously has her wand in her left hand with no time to have dropped it then picked it up again.
Continuity mistake: When Harry gets his turn to face the Boggart in Lupin's class, there is a wide shot showing the large clown rocking back and forth (viewer's left to right), with Lupin in the background bent over looking down at the floor. But, in the next close-up, Lupin is not as bent and is suddenly facing clown, contemplating whether or not he should do what he does next.
Continuity mistake: At the dinner table when Aunt Marge says "Vernon, do something" the cloth in front of her on the table is fine. When it cuts the cloth is crinkled. (00:04:30)
Continuity mistake: When one of the Weasley twins says, "Not flashing that clipping again." to Ron, we see Ron holding Scabbers. The way he holds Scabbers changes in the next shot. (00:16:20)
Continuity mistake: When Potter has entered the Knight Bus you see him passing a bed. While doing so he grabs the bed pole and lets go of it, but when it cuts you can see him still holding the pole. (00:08:55)
Continuity mistake: In the Leaky Cauldron, Harry stares out his room's window as a train passes. At the start of the next shot, as he walks toward the Monster Book of Monsters, the dresser to the left of the fireplace is visible. In the following shots the large water pitcher and wood box reach the edge of the dresser, whereas in the previous shot it is nowhere near. (00:14:55)
Continuity mistake: When Aunt Marge is inflating and floating to the ceiling, she grabs the table cloth and continues going up and take the cloth with her. Then when one of her shirt buttons pops and hits Dudley you can see that the cloth is not moving but has slid across the table a bit. It cuts to a close up of Marge and the cloth does not move, it then moves to the wide shot of the whole table and the cloth continues to move. The other button pops, hitting Dudley again, and the cloth stops moving again. (00:04:55)
Continuity mistake: In the scene where Sirius lies at the lake and Harry kneels next to him, Sirius seems unconscious, then opens his eyes in terror as he sees the Dementors. However, in the very next shot, which shows the two from above, his eyes are suddenly closed and there's no sign of movement in his face. Too big a change, too fast. (01:38:45 - 01:42:50)
Continuity mistake: When Aunt Marge is blowing up, one of her buttons pops off and hits Dudley in his forehead making him fall to the floor. We see him lying on the floor beside the table but when it cuts he is suddenly getting up right at the table. (00:04:55)
Continuity mistake: When the Dementors enter the train, there is a shot from in the carriage looking out. In this shot there is a bottle of water on a shelf and it's moving. When the shot changes to show the carriage from the outside, the water is suddenly still.
Continuity mistake: In the first scene when Harry and Sirius are by the lake, Harry sees someone conjure a Patronus on the other side; initially the silvery form of a stag is seen for quite awhile, then the circular light that broadens. However, after Harry and Hermione go back in time, as the shot faces Harry, he yells, "Expecto Patronum!" and immediately the wand emits circular light that magnifies and repels the Dementors. (01:44:05 - 02:01:00)
Chosen answer: It's not known what it is. It is left to the audience's imagination of what exactly is in the room or what some witch or wizard was doing in there. This is only meant to be a humorous bit and is unrelated to the plot. It didn't happen in the book.
raywest ★