Audio problem: At the cemetery, as Harry lies on the ground, when Voldemort leans over him and says, "If they speak of you they'll speak only of how you begged for death," in the shot facing Harry, before Voldemort continues to speak, his mouth still moves, though nothing is heard. (01:27:25)
Continuity mistake: Whilst Harry is in the bathtub in the Prefects' bathroom, the foamy bubbles on his face and body noticeably differ between consecutive shots, or disappear then reappear depending on camera angle, particularly when Myrtle is being "attentive" to him. This is not due to his moving the bubbles about. (01:23:45)
Continuity mistake: In the Triwizard champions' tent, Rita's photographer captures the moving photograph of Hermione and Harry hugging, and subsequently letting go of each other. Later, when Hermione reads from The Daily Prophet, just before Ron opens his package, in the close-up of the newspaper their hug, the release, and where they both stand are entirely different in the moving photograph. (00:54:50 - 01:05:20)
Continuity mistake: In the Great Hall, when Ron takes the dress robe out of the box, there is a plate beside Hermione which has two utensils on its left side and one utensil on its right. However, when Harry says, "It does match your eyes," and in another following shot, there is only one utensil on the plate's left side - the knife is now on the other side. (01:06:00)
Continuity mistake: When the students are dancing to The Weird Sisters at the Yule Ball, Viktor Krum can be seen at the back of the group, jumping up and down, with Crabbe/Goyle jumping up and down behind him with his hands on Krum's shoulders. Immediately after, however, Krum is seen dancing with Hermione, and Crabbe/Goyle has disappeared, with no time to move between shots. (01:16:20)
Audio problem: In the scene right before the champions enter the maze, Cedric Diggory hugs his father, Amos. When they pull away, Amos says, "That's my boy," but his lips aren't moving.
Revealing mistake: On the train to school, when HRH are in their cabin, among the different angles that are presented during this scene are the shots in which the camera either faces the large cabin window or the aisle window, directly opposite it. It is not what is seen that is the problem, it is what we don't see. When the camera faces the large cabin window we should see the scenic reflection of the window opposite it, as the train speeds along (and vice versa the aisle window), but we don't. What we do see reflected is the light colored wall beneath the blacked out window. The camera filming the shots from this angle is positioned at that window and in order not to see the outline of the camera/crew, the window was covered.
Continuity mistake: In the dorm, after Ron moans, "Yeah, that's me, Harry Potter's stupid friend" as Harry leaves his bed and walks to Ron, there is a single rectangular window beside his bed and another window about a foot above it. Later, after the Yule Ball, in the exterior zoom-in shot the crow flies toward the side-by-side double window, arched at the top, as it heads for the window sill, and in the next interior shot, the crow lands on the sill as Harry sleeps beside that window. (00:38:30 - 01:22:30)
Continuity mistake: There is a scene where Harry is holding the letter from Sirius and we can hear Sirius's voice reading the letter. The words on the letter are different from the words we hear Sirius reading. Particularly the end where Sirius says, "P.S. The bird bites" the letter says, "By the way, the bird bites."
Continuity mistake: During the second task, just as Krum and Hermione pop up from underwater and Krum's sharkhead disappears, in this specific shot Fleur (NOT another Beauxbaton student) stands on the platform in the background and her hair is fairly dry, blowing a bit in the wind. However, in a following close-up, Fleur's hair is soaked and stringy.
Continuity mistake: In the Great Hall, when Harry dribbles on himself, the plate to Hermione's right (as she holds The Daily Prophet up) has food and utensils lying on it. However, in the following shots, there is only an empty plate with utensils set on both sides, beside Hermione. (01:05:00)