
Continuity mistake: When Dolores Umbridge writes the "OWLs" on the board, the writing becomes smaller in later shots. (00:34:05)
Continuity mistake: When Dolores Umbridge uses her wand to hand out the textbooks to the class, we see a shot of Ron and Harry picking up their books and looking at the backs. In the next shot, they are both looking forward with no books in their hands. (00:34:30)

Continuity mistake: When Harry is in Umbridge's office to do lines, there is a framed photo of her beloved Cornelius and a bowl of potpourri at the corner of her desk. In the overhead shot of Harry, as he begins to write, the frame has moved towards the center of the desk. (00:36:35 - 00:37:30)

Continuity mistake: In her office, when Umbridge adds sugar to her tea, she places the spoon on the saucer. When Harry walks in and she says, "You're going to be doing some lines today," there is a close-up of the tea cup and the spoon is gone. After a brief close-up of Harry, the spoon reappears. (00:36:45)
Continuity mistake: When Harry goes to his detention, Umbridge places the spoon on the saucer. When she gives Harry the quill, the spoon has changed position. (00:36:45)

Continuity mistake: During Harry's first detention, before he starts writing and while Umbridge is still talking, he's sitting at the desk. He's holding the quill in his right hand, and his left hand and arm are resting on the desk. The shot switches to another angle, and his left arm is immediately off the desk. Umbridge is still talking, so there is no time lapse between the two shots. (00:37:10)

Continuity mistake: In Umbridge's office, Harry begins to write "I must not tell lies" on the paper and in the next close-up the writing on the paper differs. The paper itself moves on the pink mat, note the flowers in relation to the text. (00:37:45)

Continuity mistake: In the Gryffindor Common Room, when Hermione and Ron sit down beside Harry in the first shot, Hermione's left shirt ribbon hangs over her shoulder under her hair. When it cuts to the front shot, as she sees Harry's hand, that ribbon hangs properly down the front of her shirt. (00:39:10)
Revealing mistake: When Harry is going down to Hagrid's hut and discovers he isn't home, he looks over the forest discovering the thestrals. The camera moves back so Harry is also visible in the shot, but as he becomes visible, just shortly at his head to the left some of his head goes missing showing that it is a chroma-keyed background / blue or green screen. (00:40:50)
Continuity mistake: When Hermione asks if Ron ever stops eating, she has her hand up to her face. Camera cuts to behind Harry who has just walked over to them and her hand is no longer at her face. (00:43:20)
Continuity mistake: When Dolores has Sybil Trelawney in the courtyard, sending her from Hogwarts, Dolores says, "Actually, I can," and then holds up a scroll. The way and direction she holds the scroll changes between shots. (00:47:25)

Continuity mistake: When Dolores has Sybil Trelawney out in the courtyard, Sybil's suitcase in front of her is horizontal to us, even when she bumps into it, it remains horizontal. After Professor McGonagall comes over though, the suitcase is now diagonally positioned. (00:47:35)
Audio problem: When Flitwick is leading the choir, just before Umbridge obnoxiously uses the tape measure to note his height, Flitwick says, "Move those mouths," but his mouth is not in sync with the words. (00:47:50)
Continuity mistake: When Dumbledore has had a stand off against Umbridge regarding Sybill Trelawny, he turns to go back into the castle. When he does, there is a huge group of kids around him. When it cuts to a shot from the front, a huge gap has appeared in the kids instantly. (00:48:35)
Revealing mistake: Throughout parts of the film, there are points where it is obvious that Harry doesn't have glass in his glasses. One of the more noticeable points is when he is talking to Sirius in the fire. (00:50:00)
Continuity mistake: When Ron says, "Who are you and what have you done with Hermione Granger", his head is cocked to the side a little, but in the next shot, his head is facing forwards. (00:54:35)

Continuity mistake: In the Room of Requirement, before the Christmas holiday, Harry compliments the DA on a job well done, and they clap. There are two consecutive shots of the group from different angles, and between shots Cho's wand turns upside down and another girl's wand changes hands, etc. (01:01:25)
Continuity mistake: As the students are departing the Room of Requirement and all thanking Harry, the group of students around Harry completely changes between shots. It's especially noticeable as the boy with shoulder-length brown hair passes Harry twice. (01:01:55)
Continuity mistake: When Arthur Weasely is attacked by the snake, his wand keeps moving its position. First it's on the floor near him, then it is closer to his body, then he is holding it. (01:05:25)
Continuity mistake: When Harry wakes up after dreaming about Mr. Weasley's attack, you can see stubble on his neck. However, when he is in Dumbledore's office and later in Snape's, his face is clean shaven. (01:05:30)
Answer: When Voldemort originally attacked Harry, he was acting on information provided to him by Snape. But Snape's information was not complete, ergo why Voldemort lost his powers. He wants the prophecy in order to hear it in its entirety, because he believes it will give him the information he needs to kill Harry.
Cubs Fan ★