Continuity mistake: When Potter is looking at the 'Jack in the box' you can see Lupin in the background flipping his wand forward. When it cuts he has his hand and the wand behind his back. (00:42:10)
Continuity mistake: When Harry is facing the Boggart shaped as a clown, as Lupin says "Wonderful, wonderful" in the background, we can see Hermione standing right next to another girl behind Harry. But when it cuts to a wide shot from beside them we see Harry standing and we see Hermione standing behind him, but the girl next to her is nowhere in sight. (00:42:10)
Continuity mistake: In the Boggart scene, Lupin jumps in front of Harry to stop him from facing the Boggart. Between the shot directly before he jumps and the shot where he jumps, there is a dramatic change in his hairstyle. (00:42:20)
Continuity mistake: When they're having their first Defence Against the Dark Arts lesson and Harry is facing the boggart, Lupin jumps in front of Harry because he thought it would turn into Voldemort, as he later states in the movie. But the boggart had already turned into a Dementor before Lupin makes a move. (00:42:20)
Continuity mistake: After Neville's Snape/Gran Boggart, Lupin says, "Wonderful...to the back Neville. Everyone form a line." In the next two shots, first Neville heads to the back, then Malfoy shoves Neville to the side and Crabbe pushes the line of kids forward. Yet in the next shot from the front of the line, Neville already stands at the back of the line and then in the next shot, Neville walks towards the back of the line, where more kids are gathered now. (00:42:35)
Continuity mistake: When Parvati is stepping up to the Boggart, Harry is standing behind her, but while it's Parvati's turn it is not Daniel Radcliffe, it's noticeably his stand-in instead. (00:43:30)
Continuity mistake: When everyone, except Harry, leaves to Hogsmeade village, Hermione is waving as she and Ron walk directly behind McGonagall, with the last of the crowd of children ahead of them still in the courtyard. There is a short cut facing Harry now standing IN the doorway. Then the next shot from behind Harry, shows Ron and Hermione still walking past the fountain, but now McGonagall and the entire crowd of children are out of the courtyard. They could not have walked away that fast. (00:43:35)
Continuity mistake: During the DADA lesson, as Lupin jumps between Harry and the Boggart, to their right there are two tall containers, beside one another, standing against the wall with different items in them. The items change in the following shots, including the 'mirror reflection' shot. When the balloon whizzes past the back of the class and the camera spins around, the two vases are much farther apart, but in the next shot facing Harry, they're together again. (00:44:05)
Continuity mistake: During class, as Lupin's Boggart turns into a wheezing balloon in the first shot it passes Harry and heads to the back, however, in the next shot the balloon is still in front of Lupin. (00:44:15)
Continuity mistake: When they discover The Fat Lady is gone from her painting as the Head Boy says "Let me through. Excuse me, I'm Head Boy." you can see Potter, Hermione, Ron and Neville change position between the shots. (00:45:55)
Continuity mistake: During the scene where the Fat Lady is missing, the students are gathered on the stairs and Fred and George are on the top of the stairs, right next to each other. In the shot right after Ginny says, "The Fat Lady, she's gone," one of the twins is on the left, at the foot of the other staircase. He could not have moved that fast, because the two are standing beside each other when Ginny talks. (00:46:05)
Continuity mistake: At Snape's class when Hermione shows up and Ron says "Did you see her come in?", you see Potter turning around facing Hermione. When it cuts to Snape saying "Now, which one of you can tell me the difference..." you can see Potter is now looking at his book. When it cuts back Potter is facing in Hermione's direction again. (00:50:20)
Continuity mistake: When Snape is insulting Hermione on being a know-it-all while he is substituting for Lupin, he has a slide show running. The shot shows Hermione with the projector behind her. The projector now changes slides fully and stops moving. When the shot changed back to Snape, the slide is still changing. It could not be the next slide because the slide changes every few seconds. (00:53:00)
Continuity mistake: At the hospital, after Potter fell off his broom as Hermione says "No one blames you, Harry", you can see Ron standing behind her. At this time we can see the letter "H" on the cloth that is wrapped around the broom. Later, the letter "E" is visible instead. (00:54:45)
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: After the Weasley's have handed over the Marauder's Map to Potter, George puts his wand on the Map while saying, "I solemnly swear that I'm up to no good." When it cuts to a closeup of the map, you can see the way Potter is holding it changes, and the way George's wand is on it changes. (00:57:25)
Continuity mistake: When the Weasley's have given Harry the Marauders Map, after one of them says "We owe it so much", Harry opens the map. When it cuts he opens it again. (00:57:35)
Continuity mistake: When Fred and George give Harry the Marauder's Map, Harry opens it up and on the right is Dumbledore's study. In the close-up shot of Dumbledore's study, the map is drawn with much more elaborate detail for fun and dramatic flair and the actual words of the interlocking circles are written on the map extremely differently than the previous shot. (01:00:00)
Continuity mistake: 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. (01:00:00)
Continuity mistake: After Fred and George hand over the Marauder's Map to Harry, he looks down and spots Dumbledore pacing in his study, though in this shot Harry does not actually look at the upper right corner of the map, where Dumbledore's study is located. (01:00:05)
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 ★