Continuity mistake: When Harry sneaks into the restricted section of the library with his lantern, he puts the lantern down on the ledge and the light doesn't even flicker, you can tell it's a sort of lightbulb, not a candle. (01:29:10)
Continuity mistake: In the scene in the library's restricted section, Harry puts down his cloak and then his lamp. The lamp is several inches away from the cloak. When Filch enters Harry grabs the cloak and suddenly the lamp is now on top of the cloak, causing it to fall. (01:29:10)
Continuity mistake: When Harry, Ron and Hermione are running to Hagrid's hut to tell him they know about the stone (just before they see Norbert) Hermione's hair is very long, but by the time they get inside his hut and take off their cloaks, her hair is much shorter. (01:38:40 - 01:39:25)
Continuity mistake: At Hagrid's hut, when he places the dragon egg on the table, the book lies right next to the cup and saucer. Yet in the shots looking up from the edge of the table, directly in front of Hagrid and the egg/Norbert, the book and cup/saucer are far apart for these particular shots. (01:39:50)
Continuity mistake: In the scene where Harry, Ron and Hermione come with Filch to Hagrid to go into the dark forest, watch the lamp Hagrid sets down. Filch says something like "A sorry lot this, Hagrid". Then the shot cuts to Hagrid (look at the lamp) then to Filch again who says "Oh good god man, you're not still on about that bloody dragon, are you?" then to Hagrid again. The lamp changes position between these shots. (01:43:00)
Continuity mistake: In the scene where Hagrid sees the unicorn blood in the dark forest, take a good look at the silver puddle of blood. When Hagrid takes some on his fingers, the puddle changes shape and size. (01:44:30)
Continuity mistake: When Harry, Ron, and Hermione are heading to Hagrid's hut after discussing the stone, Harry says 'Why didn't I see it before?' his tie is all the way over to his right side, then when they are talking to Hagrid his tie is straight in the middle. (01:46:00)
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: In the scene where Harry, Ron, and Hermione are walking towards Hagrid after their exams, Hermione is carrying a brown satchel in her right hand. Then Harry says, "Why didn't I see it before!" and they run. While they are running she does not have the satchel in either hand, her empty left hand is visible in a few frames as she swings her hands at the side of her body. Then when they get to Hagrid she has the satchel in her left hand. (01:46:40)
Continuity mistake: In the scene where Harry figures out that Hagrid got his dragon egg from "Snape"(Quirrell), at the begining of the scene, Harry's cloak is buttoned and still is when he, Hermione, and Ron are running to Hagrid's hut. When he reaches Hagrid's hut, it is unbuttoned even though he never unbuttoned it himself. (01:46:50)
Continuity mistake: When Harry is telling the others that Snape gave Hagrid the dragon's egg, there is a group of older people walking towards them. They start to pass Harry, the camera changes angle and they are just starting to pass Harry again. (01:47:50)
Continuity mistake: When Harry, Ron and Hermione are heading to Hagrid's hut, near the end of the movie, a group of three people behind them walk into another corridor. Then a second or two later the same group walks into the same corridor. (01:50:20)
Continuity mistake: When Fluffy drools on Ron, the amount of drool changes drastically. (01:51:30)
Continuity mistake: Right after Hagrid tells the kids about playing music to Fluffy, they run into Professor McGonogall's classroom. Right before they run in, you can see a candle on a pole to the left of her desk. When they run up to her desk, it isn't there anymore. (01:51:35)
Continuity mistake: When Harry Ron and Hermione run to see McGonagall, there is an hourglass, a large book and a candle all sitting directly on top of her desk. Their positions change, especially in the shot facing McGonagall, when she says, "I'm afraid Professor Dumbledore is not here...," not only is there is another small book next to the candle, the hourglass now sits on the large book. The long iron inkwell in the middle of the desk has also been turned around. (01:51:45)
Continuity mistake: When told to relax in the Devil's Snare, Ron's hands keep changing positions instantly. (01:52:00)
Continuity mistake: In the chess scene, at the end of the (overlong) montage of shots of pieces being smashed, the White Queen turns her attention to a Black Castle. The first stroke of her sword clearly goes through the structure of the castle, which disintegrates. We cut to various different angles and watch pieces of the destroyed castle flying all over the place. Cut back to the original angle, and we see the Queen attacking again, but the Castle is completely intact - only the figure from on top of it is missing. And it can't have been the second castle, since that's Hermione's position. (01:58:26)
Continuity mistake: In the chess scene, when Ron falls off the horse, he is lying on his side on the floor with one knee bent so that one foot is higher than the other. When Harry and Hermione run over to check on him, one foot is on top of the other. (02:05:15 - 02:06:00)
Continuity mistake: Harry speaks with Quirrell near the Mirror of Erised and the arrangement of the cloth in his turban differs in two shots than in the rest of the shots. First in the shot facing Harry as Quirrell says, "While everyone else was running about the dungeon, he went to the third floor to head me off," and then in the back shot just before Quirrell unwraps the turban, after Voldemort says, "I have strength enough for this." (02:08:05 - 02:09:45)
Continuity mistake: At the end-of-the-year feast the Slytherin banner is green and gold, but their house colors are green and sliver, as evident by their robes. (02:11:00)
