Continuity mistake: When Hermione removes the blanket that makes Potter invisible you can see some snowflakes on his shoulder. It cuts and she says "Harry, what happened?", then it cut again and the snowflakes are gone. They could not have melted that fast. (01:04:55)
Continuity mistake: When Lupin is about to teach Potter the Patronus charm, you see Lupin walking with his hands in his pockets while saying "Do you have a memory? Allow it to fill you up. Lose yourself within it." When it cuts Lupin has his left hand up. (01:05:30)
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: When Hagrid is telling Harry, Ron and Hermione that Buckbeak must be executed, you see Harry in the background sitting on a rock, then stand up when he hears the news and walk away from the rock behind him. In the very next shot from behind, Harry is sitting down again (the water ripple from the small stone is visible at Hagrid's left). (01:10:00)
Continuity mistake: In the shot where Hagrid is telling Harry, Ron and Hermione that Buckbeak is going to be executed, you see Hermione (in the background) turn her head away and put her hand on her hip. In the next shot, which is a reverse shot and shows the actors' backs, she is still looking at Hagrid with her hands by her sides. (01:10:05)
Continuity mistake: When Hagrid cries out, "Buckbeak's been sentenced to death!" in the close-up, Harry Ron and Hermione are visible at the shoreline behind him. However, in the next overhead shot Ron and Hermione are much closer to Harry along the shore. (01:12:50)
Continuity mistake: When Snape points his wand at the Marauder Map and says, "Reveal your secrets," you can see Potter has his right hand down. When the scene cuts, his right hand is holding the map. (01:13:00)
Continuity mistake: In the corridor when Harry shows the blank map to Snapes he is holding it only in his left hand. When the view switches he has both hands on it, and in the next shot is again holding it in one hand. (01:13:00)
Continuity mistake: During the scene where Snape confronts Harry roaming the hallways at night with the Marauder's Map, the position of the pull strings hanging down from Harry's sweatshirt hood changes several times between shots. At first the strings are tangled together, but during later shots the strings are hanging down apart, then back to being tangled, then apart again. This happens once more when Prof. Lupin and Harry are talking immediately afterwards in the Dark Arts classroom. (01:13:05)
Revealing mistake: In the scene at night, when Harry is in the hallway with the map, the tip of his wand lights up. And later in that same scene, when Snape has the conversation with Lupin and Harry, Snape's wand does the same. However, if you look closely at the shadows on their faces, they're being lit from above, not from the wands' light below them. (01:13:45)
Continuity mistake: When Lupin and Potter enters the classroom after Lupin got the Marauders Map from Snape, Lupin says "But quite frankly, I am astounded that you didn't hand it in." The way he holds the map change in the next shot. (01:14:35)
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: In Divination, as Trelawney says, "The art of crystal gazing is in the clearing of the Inner Eye... Now what do we have here?" Ron sleeps with his elbow at the books in front of him and then wakes. In the next shot the books are between him and Hermione. (01:19:15)
Revealing mistake: When Hermione fakes reading the crystal ball, Trelawney insults her and Hermione knocks the crystal ball off the table. As the crystal ball leaves its stand it turns over and the tube used to create the smoke effect inside the ball is visible. Then as the ball rolls toward the stairs, there are no tubes visible. (01:19:55)
Continuity mistake: The first time we see Hermione punch Malfoy, she turns completely away from Malfoy, then spins round and hits him. However, when Harry and Hermione watch themselves later, Hermione barely turns away from Malfoy before she punches him, and uses a different punch too. Malfoy's reaction is different as well. (01:20:05 - 01:44:50)
Continuity mistake: In Hagrid's hut, Hagrid gets something from a cage, and then he tosses it for his creature to eat. If you look closely, you'll see Hagrid *accidently* throws the item over the creature, nowhere near its mouth, yet in the following closeup the item is still flying towards the creature's mouth, and the creature gobbles it up contently! (01:21:00)
Continuity mistake: 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.) (01:21:25 - 01:47:00)
Continuity mistake: When the jar is smashed in Hagrid's hut, the lid stays on the smashed jar, yet when Hermione picks up the stone which smashed the jar, there is a closeup of her hand holding the stone and you can see the lid of the jar on the table. (01:21:30)
Continuity mistake: In the first scene when the stone hits the jar of seed in Hagrid's hut, Hermione picks it up behind the shattered jar. Later when they have gone back in time, the stone lands next to the shattered jar among the spilt seeds. (01:21:30 - 01:47:00)
Continuity mistake: The first time Dumbledore knocks on Hagrid's door, you hear him knocking three times. Later when Potter and Hermione have travelled back in time you hear Dumbledore knocking three times, rapidly followed by four more knocks. (01:21:55 - 01:47:15)
Chosen answer: Fred and George used the map to aid them in their mischievous activities at Hogwarts, and probably had little interest in what their little brother was doing or who he might be with at any given time.
raywest ★