Continuity mistake: As Dumbledore calls out Harry's name for the Tri Wizard Tournament we see Ron sitting behind looking rather annoyed. We see him sitting up and looking to his right as Harry walks towards Dumbledore. Then as the camera switches angles he is now leaning forward.
Continuity mistake: After the 3rd task, as Moody is taking Harry back into the school, the camera cuts back to the students. Neville stands to the left (viewer's right) of Viktor Krum and the Bulgarians. In the next shot Neville stands to the left (viewer's right) of a girl, who is seen in the next shot standing beside Ron, Hermione and other students (not the Bulgarians); Neville is out of place during these shots.
Continuity mistake: In the scene where Harry is in the Pensieve, a woman sits down behind Harry. In the following shot (as Dumbledore shakes hands with someone through Harry), she walks down the stairs and sits down again. (01:39:40)
Continuity mistake: When the TriWiz chalice is revealed the camera zooms in on the chalice and you can see there is no one standing near it. When it cuts Igor is suddenly standing right behind it.
Continuity mistake: In the Gryffindor common room, after Ron heads up to the dorm, Harry realizes Sirius has gone. In the close-up of the Daily Prophet, the unwrinkled headline "Teenage Tragedy" is displayed prominently as the newspaper burns up, whereas in the previous shot (before Harry's close-up) the "Teenage" part of the headline is unseen. (00:45:10)
Continuity mistake: After Barty Crouch Jr. says, "I'll show you mine, if you show me yours," when Dumbledore grabs Harry's injured arm, the wound and the way he grips Harry's arm differs between shots. (02:11:20)
Continuity mistake: In the scene after the old caretaker is killed, Ron is seen sleeping on the bed and as Hermione is about to wake him up his arms change position. His right hand is first resting on the pillow, when it cuts it's under the pillow. (00:03:55)
Continuity mistake: In the dining hall, when Ron unwraps the box with his awful dress robes and "bonnet," the position of the wrapping, box, etc., differs between shots.
Continuity mistake: After being knocked off his broom by the Horntail, when Harry falls from the first window to the one below, tiles break off leaving a few askew. However, in some following shots the tiles are back and straight. (01:00:50)
Revealing mistake: In the graveyard, when Voldemort puts his foot on Cedric's face, Cedric's eyes are staring straight up. As Voldemort pushes, Cedric's eyes do not follow his head's movement, but continue to stare at the point that would have been straight up from his head's original position.
Continuity mistake: At the Quidditch World Cup, when Cornelius Fudge welcomes everyone, the way he is holding the wand to his throat differs in the two shots facing him and the shot from behind. (00:09:10)
Continuity mistake: During the scene where Harry is in the Prefects' bathroom after he has submerged the golden egg in the water, his wet hair keeps changing positions as he's talking to Moaning Myrtle, even though he doesn't touch it. Harry's hair changes position in consecutive shots, during other scenes in the film as well.
Visible crew/equipment: The light of the camera is reflected in the glass behind Dumbledore as he talks to Harry immediately after the Pensieve flashback.
Continuity mistake: When we first see Hermione, she puts the candle down on a chest of drawers or something similar. In the next shot it has moved to the edge of the chest of drawers. (00:03:45)
Continuity mistake: After Frank places the kettle on the burner, when he steps in front of the sink in the wideshot, the window is behind the sink, in front of Frank. There are plants on the sill that reach the window handles. However, after Frank sees the mansion light and puts the teapot down, in the close-up of the window the center plant is gone and the left plant is different. (00:01:30)
Continuity mistake: The amount of eyebrow hair, just over Moody's magical eye, differs in various consecutive shots of him throughout the film. It goes from some hair being caught under the casing, to all of it being over the casing, and vice versa; such as when he begins to feel the effects of the Polyjuice Potion diminishing, and he looks in the cabinet. (It is Moody's eyebrow over the casing, not a piece of fabric.) (00:25:20)
Continuity mistake: In the common room, when Harry meets with Sirius, there are a stack of logs at the left of the fireplace which differ between shots.
Continuity mistake: While Sirius speaks with Harry in the common room, the sweater at the corner of the couch changes position during this scene.
Continuity mistake: In the Great Hall, after Ron receives his "dress" and Harry says, "Well it does match your eyes. Is there a bonnet?" the toast caddy on the table in front of Harry moves farther down the table, between shots. (01:06:10)
Continuity mistake: When Dumbledore reveals the scar Wormtail made on Harry's arm, the blood around the scar differs in the next shot.
Answer: Voldemort's spell undid the Sacrificial Protection that Lily bestowed on Harry, but the Bond of Blood is a separate protection bestowed if the person sacrificing their lives is a relative. THAT spell is still renewed as long as Harry keeps returning to the Dursleys until age seventeen. Voldemort has removed one protection, but a second is still in place.
Captain Defenestrator