Corrected entry: When Harry meets Bill and Charlie Weasley at the Burrow, the text says that he'd never seen the two before. At the beginning of Prisoner of Azkaban, however, he had seen a picture of the entire family in a newsclip when they'd made the trip to Egypt.
Corrected entry: In chapter 12 it says "The stranger sat down, shook his mane of dark gray hair out of his face, pulled a plate of sausages toward him, raised it to what was left of his nose, and sniffed it. He then took a small knife out of his pocket, speared a sausage on the end of it, and began to eat." But that should have tipped Dumbledore off that he wasn't the real Alastor Moody. The book states plainly that Moody never eats or drinks food he didn't prepare. This is a well known reason he was considered paranoid.
Correction: The real Alastor seems to make exceptions for select people. In "Order of the Phoenix", he inspects and then eats chicken that was cooked by Molly Weasley. As a former Hogwarts student, he would have eaten food prepared by the Hogwarts elves before.
Corrected entry: On page 741, chapter 31 it says that Harry saw "horseless carriages" but he should have seen the thestrals now that he had seen Cedric dying, as thestrals are visible to those who have seen death.
Correction: JK Rowling has mentioned in an interview that this was because it takes time for the death to "sink in". She used this to fill in the plot hole so that way she wouldn't have to deal with introducing thestrals until OotP. An excuse, maybe, but fits the plot and isn't contradicted anywhere.
And, by the same logic, JKR has also clarified previously that even though Harry saw his parents die as a baby, he was too young to fully understand or remember the deaths, which is also why he hasn't seen Thestrals until much later.
Corrected entry: In Quidditch Through the Ages, it says that the first ever World Cup was in 1473, with a match being held every 4 years. Yet the World Cup in 1994 is number 422. There can't be 422 world cups in 521 years with a four-year gap in between. Calculated correctly, the World Cup that the Weasleys, Hermione, and Harry attend is actually the 131st, and it should have been held in 1993.
Correction: The only thing mentioned about the 1473 World Cup was that every Quidditch rule was broken during it. There's no mention of it being the first, and it is not given a number.
Corrected entry: When Harry decides to write to Sirius about his scar, he wonders why he didn't think of Sirius straight away. It says that Harry found out that Sirius was his godfather two months ago, but he actually found out about him before Christmas of 1993, which is about eight months previous, not two.
Correction: Although this is technically true, eight months previously Harry thought Sirius had killed his parents. He would only have written to Sirius for advice since meeting him two months previously.
Corrected entry: Harry has too many hands at the very end of chapter 34. Harry wraps one hand around dead Cedric's wrist, while "gripping his wand more tightly" in the other hand. Yet, when he summons the Triwizard Cup towards him he catches it by the handle, and a few lines later (at the very beginning of chapter 35) it says "He tightened his hold on the *two* things he was still clutching - the smooth cold handle of the Triwizard Cup, and Cedric's body". This implies Harry dropped his wand, or somehow managed to put it in his pocket, while flying through the Portkey, without loosening his grip on Cedric or the cup. A few pages later, when confronting Moody, he has his wand again.
Correction: It is totally possible that Harry grabbed both the cup and his wand with the same hand and Cedric's body with the other one. The wand and the cup's handle are not very wide.
Corrected entry: At the very end of the book Harry watches the horseless carriages about to take him to Hogsmeade, at this point Cedric has already been killed so he should be able to see the thestrals that pull the carriages as in the next book.
Correction: This has been explained in a correction to "Harry Potter and the Order of Phoenix". J.K. Rowling has herself publically explained that you do not see thestrals immediately after observing a death. The witness has to overcome the initial shock of seeing a sudden death first.
Corrected entry: On page 229, when Fred and George get beards Dumbledore sys "I suggest you both go up to Madame Pomfrey. She is already tending to Miss Fawcett of Ravenclaw." However at the ball on page 371, when Fawcett and Stebbins are found behind the bushes by Snape he says "Ten points from Hufflepuff, Fawcett." Shouldn't it be from Ravenclaw? This is from the first edition of the British version.
Corrected entry: In chapter 26, Krum tells Hermione she has a water beetle in her hair, and she brushes it away herself. In chapter 37, she says Krum pulled it out of her hair.
Correction: This would be a character mistake. She simply did not remember all the details of what happened.
Corrected entry: At the Quidditch World cup, Bagman calls flying deliberately to collide "skinning", but according to the book "Quidditch Through the Ages", the correct term is "blatching".
Correction: Character mistake or decision - Bagman could be using a slang expression, or an old term that predated "Quidditch Through The Ages".
Corrected entry: In the Swedish hardback version. The trio is visiting Hagrid just after the revelation about the triwizard tournaments revelation. They are discussing it and Hagrid says "I never thought I'd see the tournament again, in my life" implying he'd seen it earlier. Although, this tournament is the first one in over 100 years. Hagrid is supposedly 65 years old, since he was expelled in his 3rd year 50 years ago (in CoS) making him 63 in CoS and 65 in GoF.
Correction: Hagrid never implies anything, you inferred it. Given it was the first one in 100 years, he was surprised he lived to see a tournament. This would be akin to someone born after 1972 saying "I never thought I'd see man land on the moon again."
Corrected entry: In Chapter 17, Karkaroff says to Moody, "I heard you recently got it into your head that one of your birthday presents contained a cunningly disguised basilisk egg. However, in Chamber of Secrets, Hermione's page from the library book about basilisks says that a basilisk "is born from a chicken's egg, hatched beneath a toad. Moody would have had to hatch his birthday present under a toad for it to be a basilisk.
Correction: Karkaroff was trying to characterize Moody as being excessively paranoid to the point of not thinking clearly. Karkaroff's point is that any rationally thinking being would know a basilik has to be hatched beneath a toad, but Moody, in his paranoia, was not thinking clearly enough to realize that.
Corrected entry: In Order of the Phoenix Harry can see Thestrals because he claims to have seen Cedric die. However, in Goblet of Fire, at the graveyard, it says that Harry's eyes are closed due to the pain in his head. All he sees is green light and therefore did not see Cedric die.
Correction: First of all, had this been a mistake, it should be listed under "Order of the Phoenix", as that's were the continuity change would have been noticable. However, this is not a mistake. To say "see someone's death" is a figure of speech meaning you were there when it happened, it does not mean you have to stare directly at them in the precise split second life departs the body. Harry still witnessed Cedric's death, even if his eyes were closed.
Corrected entry: In chapter 22 of this book it says that Harry and Cho Chang are a year apart. But in Prisoner of Azkaban, it states they are two years apart.
Correction: Chapter 13 of Harry Potter and the Prisoner of Azkaban states Cho Chang is a fourth year at this time. Making her one year apart from Harry.
Corrected entry: When Moody demonstrates the Imperius Curse, the book says he used it on Harry four times. However, later in the book, it says "And Harry felt, for the third time in his life, the sensation that his mind had been wiped of all thought. It should be the fifth time because he had already experienced the Imperius Curse four times before.
Correction: Harry had already learned to fight/repell the Imperius Curse by Moody so the blanking effect would not be the same the third and fourth time around.
Corrected entry: After Hermione dropped Muggle Studies, she says she has the same amount of classes as Harry and Ron. But she still had Arithmancy, Care of Magical Creatures, and Ancient Runes, not including the mandatory ones. She still has more than Harry and Ron, who only have Divination and Care of Magical Creatures.
Correction: She never says that she has the same number as Harry and Ron. She only says that she will be able to maintain a normal schedule and will not need to use a time turner to get to all her classes. By the way, this entry is on the wrong page because the line in question is actually at the end of Prisoner of Azkaban.
Corrected entry: On page 152 Percy says "It was a tad unwise to make a public statement without clearing it with his [Arthur Weasley's] head of department first." However, in book three, it is stated that Mr. Weasley IS the head of his department.
Correction: Mr. Weasley's department, the Misuse of Muggle Artifacts Office is a subdivision of the Department of Magical Law Enforcement. Presumably it was the head of THIS department (revealed in the fifth book to be Amelia Bones) whom Percy was referring to.
Corrected entry: In book 2, it says Myrtle haunts the U-bend of the toilet, but in book 4, it says she haunts the S-bend.
Correction: An S bend is just 2 U bends. All drains are S bends to let water out and keep gases down.
Corrected entry: For an alleged spectator sport, the Triwizard Tournament is remarkably unfriendly to spectators, with the First Task the only one of the three in which they are able to witness the action going on (since the second task takes place at the bottom of the school lake and the third in an overgrown maze of hedges). Watching the three tasks is presumably the whole point of the tournament, and the justification for cancelling an entire year of Quidditch, a much more spectator-friendly game.
Correction: For one thing, at no point is it ever stated to any degree that the Triwizard Tournament is a spectator sport. Quidditch is cancelled so the champions can focus on the tournament instead of the Quidditch season, and so the maze can be grown on the pitch. For another, the audience for the third task is sitting in bleachers a hundred feet up; they can see everything just fine.
If they could see everything in the maze, Moody would have been caught helping, Krum would have been arrested for using unforgivable curses and everybody would have freaked when Harry and Cedric disappeared for a few hours.
This is quite a good plot hole IMHO. They ship several years' worth of students from two schools to Hogwarts for the Tournament and cancel Quiddich etc. for everyone, for the purposes of the tournament. It's not like they share classes or anything - the Ball and that's about it. If not a spectator sport - and what sport isn't? - why not just send the champions off by themselves and not disrupt anyone else. And why have the crowds at the lake, staring at the surface of the lake for hour?
It's not a sport. It's a brutal competition between the 3 best students of 3 schools. All year around the students of 1 year of the other 2 schools are at Hogwarts and the tournament is going on. There are still classes, since only 3 students are supposed to participate anyway but if they don't allow students to go watch the 3 tasks when they happen they'd probably refuse to follow classes and riot. So they let them watch, even though they can't see anything of it.
Correction: While this is true, you can't rule out the possibility that the text meant Harry had never seen Bill and Charlie in person before.