Continuity mistake: When Xenophilius draws the Deathly Hallows symbol, he draws it so that the bottom of the line touches the bottom of the circle. The shot cuts away and back again when he draws the triangle, but the line is no longer touching the bottom of the circle. (01:49:40)
Continuity mistake: When Hermione is being tortured by Bellatrix in Malfoy Manor, we see a closeup of Hermione crying, and then Bellatrix reaching over to Hermione's right arm to carve "Mudblood" into it. But in the next shot, we see Bellatrix carving it into Hermione's left arm instead. (01:59:40)
Continuity mistake: In the forest, when Hermione is sitting with her back against a tree, reading, the book changes position between shots after Harry walks over to her. In a close-up, the top of the book is over her knees, in the following wide-shot, the book is below her knees, and then moves back to its original position in the next shot. (01:33:10)
Continuity mistake: As the Death Eaters disrupt Bill and Fleur's wedding, Ron holds Hermione's right hand and Harry holds her left hand as she disapparates with them in tow. However, when they apparate onto Shaftesbury Avenue, Ron and Harry's positions have switched, now Harry holds Hermione's right hand and Ron holds her left hand. (00:36:05)
Continuity mistake: At the Ministry of Magic, as Yaxley is reprimanding Ron, who is disguised as Reg Cattermole, the initial on Yaxley's Ministry tie pin changes direction. In one shot, the letter "M" is tilted to the left, and in a subsequent shot, it's slanted in the opposite direction.
Continuity mistake: Luna's dad pulls Harry aside at Bill and Fleur's wedding to tell him that he fully supported Dumbledore and now supports Harry. He's wearing a silver pendant in the shape of the Deathly Hallows symbol. In the close-up of the jewelry, it is over his yellow vest. In the consecutive medium shot, it is partly under the same vest. (00:33:00)
Continuity mistake: When Hermione removes her parents' memories at the start of the film, she points her wand at them and says "Obliviate", turning her wand hand so that her palm faces inwards/upwards. In the very next shot, however, her palm is facing outwards/downwards, with no time to change in between. (00:02:20)
Continuity mistake: When Hermione and Harry are sitting on the rocks by the cliff, Hermione is putting down a closed book. When the camera angle switches to seeing Hermione from behind, it appears the wind has blown the book open, but when the camera switches back to a front view, the book is closed again. One final switch, and the book is open yet again, flapping in the wind. (01:23:15)