Revealing: In the first overhead shot as the Dementors swoop down towards Sirius and Harry, Sirius lies in a particular position. During the Dementor attack his clothes move, then after Harry's Patronus repels the Dementors, Sirius breathes again and he now lies flat. After Harry collapses, in the last overhead shot, Sirius and his clothes lie in precisely the same position as the first overhead shot. His position differs later, in the repeat timeline as well.

Continuity: When Potter is messing with Malfoy and the other two kids outside the Shrieking Shack, as Potter drags down the cap on one of the kids, you can see the kid's scarf is suddenly tied. It wasn't tied in the earlier shot, and Potter could not have tied it that fast.

Continuity: While Hermione tries to coax Beaky to follow her and Harry, in the wide shot she and Harry stop, she tosses the ferret and throws her hands up in the air. In the next two close-ups their positions differ.

Continuity: While Harry is in Lupin's office, Lupin's coat, which lies on a trunk, changes its position multiple times, as does the trunk.

Continuity: When in the Leaky Cauldron, there is a man offering Harry food. He holds a bowl of nuts towards Harry, and in one shot he holds the bowl with two hands, yet in the following shot he is holding it with one hand.

Revealing: When Harry first opens the Monster Book of Monsters, when looking closely, you can see the hollow part of the book that spits out the paper. Easiest to see when Harry is looking under the bed.

Continuity: During the class with Hagrid, sometimes Ron has his Monster Book of Monsters under his arm and sometimes he doesn't have it.

Deliberate "mistake": The song "Something Wicked This Way Comes" is staged with a mixed choir, with a majority of girls. However, to the trained ear, you can tell the song is sung by an all-boys chorus.

Continuity: When Ron gets Scabbers back in Hagrid's hut, immediately afterwards Hermione says, "I think you owe someone an apology". Later, when future Harry and Hermione hide behind the pumpkins by Hagrid's hut, you can see Ron getting Scabbers back. So right after this Hermione should be saying, "I think you owe someone an apology." But future Harry and Hermione talk for a little bit, and when they're done, Hermione says the line. Shouldn't this line have already passed? (This can be easily checked on the closed captioning.)

Continuity: When Harry, Hermione, and Ron are hiding behind Hagrid's pumpkin patch in an attempt to hide themselves from Fudge and Dumbledore, Hermione turns around at the sound of a 'crack' in the forest, she then turns to her left and runs with the others. Later, when seen from Hermione's view reliving the past, Hermione at the pumpkins turns to her right before running with the others.

Continuity: When Harry storms into the pub in Hogsmeade, the camera follows his footprints to the door, and at the door is a large clearing where there is no snow, because the ground is sheltered by the door's porch. Yet in the following shot the clearing has decreased greatly.

Continuity: In the "Care of Magical Creatures" scene, Hermione gets a fright and there is a close up of her grabbing Ron's sleeve. From a different shot seconds later, you can see her grab his sleeve again in the distance.

Continuity: When Harry is about to pass out and says "Sirius", he says it in two breaths (Siri-us). The second time, when Harry and Hermione are watching this same exact scene occur in time, he says it in one breath (Sirius).

Continuity: When the Whomping Willow kills the blue bird flying towards Hagrid's home, the loose branches from one shot are not visible in the second shot.

Continuity: Just before the Knight Bus starts to squeeze between the two double decker's, watch the annoying Shrunken Head at the front of the bus. There's a long shot as the bus is just about to squeeze, and the head turns round to face Harry. There's a shot of Ernie pulling the leaver, then a close up of the head as it turns round again, and says, "Mind your head."

Continuity: When Harry falls back after being startled by Sirius the dog, the Knight Bus headlights shine glaringly bright light all over Harry and the trunk. Yet in the next shot facing the oncoming Knight Bus, Harry and the trunk are barely lit by the headlights, which are nowhere near as bright. In the previous shot the light is obviously provided by spots.

Continuity: As Marge is inflating, there is a close-up of her knees, as the skirt rises revealing the garters. In this close-up her cloth napkin is on the table right in front of her, though in the previous and following shots it is on the floor.

Continuity: When Lupin is turning into a werewolf and Sirius comes at him while saying, "Remus, my old friend. Have you taken your potion tonight?" Lupin's shadow on the ground change position in the next shot.

Continuity: When Harry and Ron are looking at the clipping from Egypt the clipping lies on the table. Its position changes in the shot when the Weasleys arrive.

Continuity: When Harry and Hermione are back in time and hiding in the woods. Notice that Hermione has a bruise/sore on the bottom corner of her lip that keeps appearing and disappearing.