Audio problem: When the trio are on the Hogwarts Express, we hear Harry say "What was Draco doing with that weird looking cabinet and who were all those people" but the subtitles say it was Ron who said that.
Continuity mistake: Tied round Dumbledore's beard is a thin silver strand, with dangling silver balls, that changes position and the height of the silver balls differ in consecutive shots, depending on the camera angle throughout the film. For example, when Dumbledore and Harry first pay a visit to Slughorn.
Continuity mistake: In Potions class, when the students prepare the Draught of Living Death, as Harry tells Hermione, "Crush it, don't cut it," the way he holds/squeezes the Sopophorous Bean has instantly changed from the previous shot.
Continuity mistake: At the Burrow, when Tonks and Lupin are at the front door with Mr. and Mrs. Weasley, it cuts to an exterior shot of Harry looking out the window with his arm leaning across his knee in front of him, but in the next interior shot his arm is down at his side.
Continuity mistake: At Slughorn's party, Harry and Slughorn have their picture taken. Before and after the flash the background changes completely without enough time to change.
Continuity mistake: When Dumbledore is talking to Harry about Horcruxes, Dumbledore's hair is blowing and messy in one shot, but fine in the next shot.
Continuity mistake: In the Great Hall, when Lavender's eyes are shooting daggers at Ron and Hermione, Harry's arms/hands keep changing position on the table as the three of them speak.
Continuity mistake: At Aragog's funeral, there is a long shot of Slughorn, Hagrid and Harry standing by Aragog. However from this angle Aragog is not here. Given the angle you should be able to see Aragog's body.
Continuity mistake: When the Death Eaters attack Ollivander's, the debris/fire and the bodies lying on the ground differ between the overhead and next close-up.
Continuity mistake: At the Burrow, when Ron takes a seat between Ginny and Harry he is holding a pedestal plate full of pies, which change in the next shot facing the other way.
Continuity mistake: In Hagrid's hut, when Slughorn and Hagrid are drinking, the cups/bottle on the table change position between shots.
Continuity mistake: When Luna and Harry pass through Hogwarts gate, the parchment and wand in Flitwick's hands differs between shots.
Continuity mistake: When Ron is foaming at the mouth, the foam is either there or it's not, depending on the shot.
Continuity mistake: The glass that is smashed in the Great Hall's window behind the staff tables changes somewhat from when Bellatrix smashes it, and when we are shown the Great Hall empty.
Continuity mistake: When Dumbledore and Harry are talking about Horcruxes, Harry's hair is nice and combed in one shot. The camera cuts to a side view and his hair is now messy.
Continuity mistake: In the Great Hall, when Ron (wearing his Quidditch uniform) asks Hermione about the Slug Club, Ron's right arm lies on the table in front of him in shots from behind, but in shots facing him his right arm is down beside him.
Continuity mistake: When Hermione opens the locket to read the note, the locket and chain's position changes in her hand between consecutive shots.
Continuity mistake: At the end of the movie, there is a long shot of Hermione, Ron and Harry atop the Astronomy tower. In this long shot Hermione's hands are in different places compared to the previous close up.
Continuity mistake: During the Slug Club's dessert, as Slughorn speaks to the students, their ice cream, syrup, thin wafers, spoons, etc, change depending on the camera angle.
Other mistake: When Professor McGonagall is talking to the trio about the necklace incident and Professor Snape is walking by in the background, he stops just before she calls him over.
Chosen answer: Snape wants to know how Harry knew Sectum Sempra. As shown by him using Occumelancy to see where his copy of Advanced Potion making is. But at the same time, if Snape punished Harry for a spell in a book, Harry could show it to Dumbledore, who would recognise Snape's handwriting. Additionally, Harry was certainly punished in the book - he got detention with Snape every Saturday for the rest of the term. The movie most likely had to cut this for time issues, and also perhaps because the scene is more dramatic if Snape only silently glares at him.
Ssiscool ★