Harry and Hermione get their wands taken from them when they are caught using Umbridge's fire. After the centaur attack the others break free and come to meet Harry and Hermione. After this point they have their wands, even though nothing was mentioned to say how they got them back. [If you read the text closely enough, it says that Ron hands Harry and Hermione's wands back to them.] Corrected by Cubs Fan

In the practical exams for their OWL's, the students are called in alphabetical order by last name. Yet Harry is in at the same time as Hannah Abbot for one of their exams. Abbot and Potter should not be together. [However, at an earlier point, Malfoy was still taking his exam when Harry walked in. Since Hannah Abbot's exam went so poorly, it is likely that she was still being tested when Harry walked in.]

In the British version of book 5, it talks about Algernon Rookwood, but in book 4, it talks about Agustus Rookwood. [These could very easily be two different people.]

In the chapter where Harry and company are having their Care of Magical Creatures with Prof Grubly-Plank, she says to turn in their drawings of bowtruckles at the end of class. In a later chapter, Harry says he has to finish the bowtruckle drawing. [It's not unlikely that the professor was not satisfied with Harry's drawing, and made him do it again as extra homework.] Corrected by Twotall

In Chapter 17 Harry hands an injured Hedwig to Professor Grubbly-Plank who says "Thestrals will sometimes go for birds, of course." The next paragraph states that "Harry neither knew nor cared what Thestrals were". However, in Chapter Ten there is a discussion about them between Luna Lovegood and Harry who can both see them pulling the carriages, as well as a paragraph where Harry is pointing them out to Ron. [True, but at those points in time, Harry didn't know what they were called. Only after Hagrid returned and resumed teaching did Harry learn why he could see them and Ron and Hermione could not.] Corrected by Cubs Fan

In book 1, it says that James and Lily Potter were Head Boy and Girl. You have to be prefect to become head boy or girl. In this book, Sirius tells Harry that his father (James) was not a prefect. [No you don't. JK Rowling said so herself you don't have to be a prefect to become head boy or head girl.]

At the beginning of the book, Harry is given a gift by Sirius. This is a gift that he does not open until after Sirius is dead, and he finds it to be a communication mirror. Not once in the rest of the entire book is this present mentioned. Even when Harry uses the fireplace and risks everything to talk to Sirius, Sirius does not mention opening his present, and during the weeks of Christmas break, when they are actually face to face, no one mentions it either. This is a valid plot hole because it is highly unbelievable that such a valuable gift would have ended up in Harry's hands and not used. With that mirror in use, most of the miscommunication in the book would have been avoided, making the plot seem suspiciously forced. [It states explicitly that Harry pushed it out of his mind to avoid risking Sirius's freedom. It wasn't at the beginning of the book that he received it either, it was a Christmas gift; and no one knew about it except Harry and Sirius, hence the lack of discussion. Simply put, Harry deliberately forgot all about it. He even laments having done so after he finds out what it was.] Corrected by Phixius

Hermione is knitting hats to free the house elves of Hogwarts. but the elves don't belong to her, they belong to Dumbledore. So technically they can't be freed by students, only Dumbledore. [Where's the mistake? It never says any of the elves were freed. Only that they found the attempt insulting.] Corrected by Phixius

In chapter 28, it says that every person in the school seemed to know how Dumbledore had overcome two Aurors, the high inquisitor, the minister for magic, and his junior assistant. Percy is the minister junior assistant, and Percy wasn't in the office with him, as he left moments after Dumbledore's "confession" to send his notes to the Ministry. [Uhm, It's certain that since everyone in the school knows, it has been spread around person-to-person. Not everyone would have known Percy was out of the room, so they would have just told others who had been with the minister as he entered the school, figuring that Dumbledore must have beaten them all.]

In preparation for their exams, Parvati and Lavender were making their pencil cases race around. However, they use quills, so why would they have a pencil case? [A pencil case is a generic term for a receptacle in which one keeps stationery. Not specific to pencils, and avoids confusion that might have been caused by calling it a "quill case".]

In the chapter Luna Lovegood, Harry sees the thestrals for the first time, because he saw Cedric die at the end of last term. But he didn't see the thestrals when he left Hogwarts before the summer. [JK Rowling explained this at the Edinburgh Book Festival. She specifically said that it was not a mistake, and that she had thought about this carefully. She explained that 'anyone who has suffered a bereavement knows that there is the immediate shock that takes a little while to appreciate fully that you will never see that person again. Until that happened, I (JK Rowling) did not think that Harry could see the Thestrals'. So, in other words, it wasn't until the death of Cedric had sunk in that he was able to see the Thestrals.]

In chapter 27, Fudge says, "Or is there the usual simple explanation involving the reversal of time, a dead man coming back to life, and a couple of invisible dementors?" Fudge never knew about Hermione and Harry using the Time-Turner to rescue Sirius in book three. [Fudge did not really know about the Time-Turner, but he wanted to make a point about how he considers Harry's stories too extravagant and fantastic to believe in, and exaggerates. There were never any "invisible dementors" either, as all of this is something Fudge makes up to illustrate his point.] Corrected by Twotall

In chapter 38, it says that Tonks was wearing a t-shirt that says "The Weird Sisters". But in the illustration at the beginning of the chapter, you can see that only "erd" is visible, but it should be "ird", because the e comes before the i. [Illustrations are not part of the text, and should not be considered book mistakes. Artwork on DVD cases are not considered movie mistakes, for the same reason.] Corrected by Twotall

When discussing former Defense Against the Dark Arts teachers, it's brought up that "one sacked, one dead, one's memory removed and one locked in a trunk for nine months." Lupin is the sacked one that's referred to, but he didn't get sacked, he resigned. [Character decision - Lupin was practically sacked, but was given the option of resigning first. He still lost his job, and not by his own volition, which is the same as being fired. Lupin was simply allowed to put a nicer name to it, that's all.] Corrected by Twotall

Dennis Creevey is a second-year student, yet somehow he is able to go into the Hog's Head for the D.A. meeting. Only third years and up are allowed into Hogsmeade. [As seen several times in the books, it is quite possible for Hogwarts students to break the school's rules, if they want it enough. Harry & co. (not to mention the Weasley twins) do it all the time.] Corrected by Twotall