Continuity mistake: During the flying lesson scene, some strands of Hermione's hair have very deep crimps on both sides of her face in a few shots. In other shots the crimps are far looser and still in additional shots, there are no crimps whatsoever. (00:55:25 - 00:57:10)
Continuity mistake: During Madame Hooch's flying lesson, in a close-up Ron says, "Up! Up!" to his broomstick. In the next wide shot of all the students, Ron stands next to Harry, who holds his broomstick, and just before it cuts to the next shot, Ron visibly grips his broomstick as it floats up to his hand, as well Seamus, who grabs hold of his too. Yet, in the next shot Seamus still says, "Up! Up!" and in Ron's next close-up, he still says, "Up!" to his broomstick still lying on the ground, which promptly smacks him in the head. (00:55:30)
Continuity mistake: When Malfoy throws the Remembrall, he throws it back toward the crowd of students from which he came, yet Harry has to fly back across the courtyard toward the students after catching the Remembrall. (00:56:20)
Continuity mistake: In the scene where Neville lost control of his broomstick during flying lessons, we see a shot of him going straight towards the castle wall (this is the first time he sees the wall). When you see him zooming towards the wall there are many windows. However, when the shot changes and Neville actually bumps into the wall with his broomstick, there are no windows seen. (00:56:35)
Continuity mistake: During Neville's ill-fated flying lesson, as he approaches the statue from behind, we see that the statue is placed atop a round turret with alternating levels of bricks around the top of the turret. Neville's robe then snags on the spear of the statue. When we see the front of the statue as Neville falls, the statue is now standing atop a flat, level section of wall. (00:56:55)
Continuity mistake: When Madame Hooch leaves with Neville to go to the hospital wing, Seamus holds his broomstick with the bristles on the ground as Malfoy ridicules Neville. However, as Malfoy steps on his broomstick and then flies away, the bristles on Seamus' broomstick are now at the top. Then when Harry takes off on his broomstick, the bristles on Seamus' broom are on the ground once again. (00:57:30)
Continuity mistake: Malfoy holds Neville's Remembrall and as he begins to deride Neville, Hermione stands between Harry and Seamus. Yet in the next close-up Seamus is right next to Harry and then inches over a bit as Harry moves closer to Malfoy. (00:57:35)
Continuity mistake: When trying to catch Neville's Remembrall, Harry flies straight for McGonagall's window. The window visible in the wide shot has a horizontal beam that crosses the center vertical beam, yet the window visible in the close-up just has the vertical beam. The number of stones at the sides differ as well. (00:58:30)
Continuity mistake: When Harry lands and gets off his broom after catching the Remembrall during the flying lesson, he starts running over a shadow of the castle. But in the next shot, it has either been shot at a different time of day, or he has gone past the shadow and has run further up the path. (00:58:55)
Continuity mistake: When Harry, Ron and Hermione go to the third floor corridor for the first time, they all run into the corridor with Fluffy in and close the door. In the next shot, Ron walks through the door again and closes it again. (00:59:40)
Continuity mistake: When Hermione shows Ron and Harry the Gryffindor Quidditch trophy, in the close-up of James Potter's name, Harry's reflection is visible on the badge. In the reflection, the points of his white shirt collar and a good portion of his tie are seen, whereas, in the shots facing Harry the collar points are tucked into his sweater and only the tie's knot is seen. (01:00:35)
Continuity mistake: When Hermione is saying to Harry and Ron "You won't make a fool of yourself, it's in your blood," Harry and Ron have several books with them, but straight after, right before the staircase moves, they have no books in their hands. (01:00:35)
Continuity mistake: When Harry, Ron, and Hermione are in the staircases, watch the pictures on the right: they are not moving, but when the camera changes all the pictures are moving. (01:00:50)
Continuity mistake: When Wood takes Harry out to see the Quidditch balls, he sets down the bat right against the box holding the balls. When Wood goes to open the box, you see the grass where the bat should be. And then he picks up the bat, which is not where it was originally placed. (01:01:30)
Continuity mistake: When the three heroes first go into the forbidden corridor and are spotted by Filch's cat, they run away, through the large horizontal corridor which must be at least 40 metres long (since we are given two long shots of it and neither of them connects by any physical object). They hide behind a wooden door which they close afterwards. When Filch looks in the other end of the corridor then leaves and we hear a very silent click, Hermione says 'Filch is gone.' The door they're behind does not seem to be open at all, and even if it is open a bit on the right side, Hermione's on the left side of it so she can't see whether Filch is gone or not. And can you hear a silent click of a closing door from forty metres? (01:01:45)
Continuity mistake: When Quirrel collapses in the great hall on Halloween, his feet are quite far apart. Camera cuts to everyone rushing for the door, and Quirrel's feet are practically touching. (01:05:30)
Continuity mistake: In the scene where Hermione is coming out of the bathroom stall her head is down and you can see that the part in her hair is crooked, but when she is under the sink you can see that now her part is straight. (01:09:55 - 01:10:50)
Continuity mistake: When Harry and Ron rush into the bathroom after the troll to rescue Hermione, they push open the closed doors, but wouldn't they be open from when the troll went in there moments before? The doors can't have closed after the troll as when Harry and Ron push open the door, it stays open. (01:09:55)
Continuity mistake: When the troll enters the girls' lavatory, in the wide shot as Hermione walks backwards towards the cubicles, the room becomes brighter from the storm. With this extra bright light it is simple to see that the wall between the 2nd & 3rd cubicles actually touches the floor, unlike the other cubicle walls. Yet, in the overhead shot as the troll's club slams into the cubicles, Hermione is lying under that very wall crawling away. (01:10:05)
