Continuity mistake: When Petunia covers Dudley's face, her hands alternate from right over left to left over right. (00:05:30)
Continuity mistake: When Harry walks into Gringott's for the first time, if you look at the pattern on the floor he jumps forward about 5ft instantly. (00:21:10)
Continuity mistake: When Hagrid goes to leave, the door has a gap visible at the top where you can see the rain. When Hagrid grabs hold of the top of the door the gap has vanished. (00:17:20)
Continuity mistake: When Fluffy drools on Ron, the amount of drool changes drastically. (01:51:30)
Continuity mistake: The amount of shirt that is untucked on Ron just after their exams is constantly changing from a lot to a little. (01:46:20)
Continuity mistake: When Neville first takes off during the 1st flying lesson, Ron covers his face with his right hand. When the shot changes, his hand is no longer over his face. (00:54:20)
Continuity mistake: On his first night in the castle, Harry is sat on a window ledge with Hedwig. In this shot, his feet go from resting on their sides and crossed at the ankles to flat and uncrossed. (00:48:50)
Visible crew/equipment: As the first years amass at the top of the steps prior to being sorted, a strong, round white light is in the glass behind McGonigal. (00:38:10)
Continuity mistake: When we first see Harry drawing a cake in the dirt, his hand is in the shadow created by the sofa when lightning strikes. When we see a closeup of the drawing, his hand is in the light. (00:12:50)
Continuity mistake: When the letters start flying through the letterbox they are coming in with the address facing down and the red seal facing up. When Vernon says they are going away, the letters are now addressed side up and red seal down. (00:12:15)
Visible crew/equipment: When Dumbledore gives the order to the students to follow the Prefects towards their dorms after the troll came out from the dungeon, just a moment before Harry warns Ron that Hermione is unaware of what is happening, some light reflectors simulating lightning are reflected on the glass above the pathway where the students come from. (01:05:55)
Revealing mistake: When Ron is hit by the Queen during the chess game, the stunt double is visible on the horse just a few moments before he falls. (01:59:00)
