Corrected entry: In the scene where Molly Weasley and Bellatrix Lestrange are dueling, Molly makes the first move and casts a spell at Bellatrix. After Bellatrix retaliates the same scene that was used when Molly casts the first spell is used again.
Corrected entry: In the midst of the battle, Ron and Hermione are confronted by Nagini. In the first shot, they are on opposite sides of the snake, however, after some cuts of Harry and Voldemort dueling, they are on the same side of the snake running down the staircase together.
Correction: Since we are shown cuts of Harry dueling Voldemort, it is completely feasible that they were able to get past the snake in those few seconds.
Corrected entry: Normally, when you get hit by the killing curse, you fall to the floor dead and whole. When Voldemort gets hit, he dissolves into ashes, and doesn't stay as a whole.
Correction: Voldemort's soul had been so severely damaged by being shredded into the seven horcruxes that the small portion remaining inside him could have been insufficient to keep his body intact. It was also a resurrected body, and may have been weaker than normal, making it react differently to the killing curse.
Corrected entry: When Harry and co. change clothes after jumping into the lake, Harry puts on a long sleeved gray shirt that has a dark collar. Later, in the "limbo" scene, he is shown wearing the same gray shirt with dark collar but the sleeves are short.
Correction: The "Limbo" scene has no relationship whatsoever to what Harry was wearing after the Trio jumped into the lake. After being hit by Voldemort's curse, everything is occurring inside Harry's head. Whatever he sees is from an altered reality. You'll also notice all his clothes look clean and new, Harry is perfectly groomed and his hair neatly combed, he no longer has cuts or bruises, nor is he wearing his glasses, as he would have no need for them in a state between life and death. Everything around him is altered too, such as the train station, and even Dumbledore, who looks fully restored to health. Harry's shirt is just a style he has often worn throughout the series, so it is logical he would see himself wearing some version of it.
Corrected entry: When Voldemort says to Snape in the Boathouse "Only I can live forever", Snape's reply is "My lord". Look at his shirt and you'll see that it's buttoned. But when Voldemort casts Sectumsempra on him his button is undone and his white collar is visible.
Corrected entry: In the scene where Lavender dies, her head is facing away from us while Fenrir Greyback is biting her neck. After Fenrir is blown out the window, her head is turned toward us, conveniently so we can see who just died.
Correction: That is wrong. When Greyback is attacking Lavender and is then blown out the window, her head is pointing to the left-hand side of the screen and her face is turned away. The camera shifts its angle, and Lavender is now seen from the "opposite" side, with her head still tilted in the same position, but her body is now pointing to the right, showing her face to the audience.
Corrected entry: When Harry and Voldemort are duelling in the castle (after Voldemort had discovered that Harry is not dead), Harry drops the basilisk fang, and it is destroyed by Voldemort. However, minutes later, Ron somehow has it when he and Hermione are trying to kill Nagini.
Correction: In an earlier shot, Ron has an armful of the fangs. Presumably the one he has is one of the others.
Corrected entry: When Voldemort breaks into the nursery where Lily and Harry are, Lily is holding Harry. But in the Snape flashback scene, Lily is talking to Harry in his crib before Voldemort breaks in. Also, when Voldemort kills Lily, Harry is in the crib again.
Correction: Yes, but there is no mistake. Lily's talking to Harry before Voldemort gets to the room. When Voldemort gets near, Lily gets Harry and closes the door (as seen in Philosopher's Stone). Before Voldemort kills Lily, she puts Harry in his crib again (as seen in PS as well). After she has died, he stays in his crib. No mistake.
Corrected entry: When Ron and Hermoine go back to the Chamber of Secrets to get a basilisk fang, Ron speaks Parseltongue and then explains to a surprised Hermione how he knows it. The second film established that one needs to speak Parseltongue to open even the bathroom entrance to the Chamber. Therefore, Ron would have explained himself before they reached this point.
Correction: Not necessarily. Ron might simply have not thought to explain how to open the door to Hermione until they reached it.
Corrected entry: Hogwarts castle's design changes: Courtyard is now outside the dining hall, whereas in the rest of the movies there was a flight of stairs.
Correction: As explained in an answer to a question on this site, the stairs and the hall inside has been completely destroyed in the battle. That's why it appears as if the Great Hall leads directly into the courtyard.
Corrected entry: When the trio destroys all the horcruxes, Voldemort's face is seen in its current form. As with the diary when it is in use in the Chamber of Secrets, you are given Voldemort's soul as it was when the horcrux was created (as a teenager). Yet when every other horcrux is destroyed, the spirit's demon/noseless form is seen.
Corrected entry: Harry collects two tears from Snape as he dies however when he pours the tears into the pensieve he pours a larger amount of liquid than the two tears collected by harry.
Corrected entry: Harry Potter disarms Draco Malfoy and gains full power of Malfoy's wand and the Elder Wand. However, in the first year, all wizards are taught to disarm each other, yet the possession of their wands never change.
Correction: It is only under specific circumstances that a wand "may" change its allegiance to a new owner. It does not automatically happen every time a wizard is disarmed. Also, because the students are only learning how to perform the spell, it is not a true combat situation - they are only practising. The wands, being somewhat sentient, are able to detect the difference. New information on "Pottermore" also reveals that the more powerful wands tend to have stronger loyalty to their masters, making them more difficult to "capture."
Corrected entry: When Professor McGonagall uses a spell to animate the knights, they are in minority than when you see them on the bridge. On the bridge they are at least twice, maybe triple as many. (00:40:45 - 00:53:50)
Corrected entry: When we initially see Voldemort near Hogwarts he is wearing a black cloak, yet, in the battle scene it suddenly changes to light blue.
Correction: It's still black...the moonlight makes it look lighter.
Corrected entry: Luna was left at Shell Cottage, but is in the scene already as Harry arrives in the room of requirement, dressed in the same clothes she had on at Shell Cottage.
Correction: So she left Shell Cottage some time after they did and went straight to Hogsmeade, where she gained entry to The Room of Requirement. Harry, Ron, & Hermione made a stop at Gringotts first, then rode a dragon around Britain for a while. Not even the slightest haste needed for Luna to get to Hogwarts first. She is also wearing different clothing.
Corrected entry: During Snape's death scene, he dies with his eyes open. In the next shot, his eyes are closed.
Correction: The later shot blurs Snape's face slightly, which could cause the eyes to appear closed.
Corrected entry: In the epilogue at the end of the movie Harry has no scar.
Correction: Actually, the scar is present but very difficult to see. It is very thin and faded, as would be expected nearly 20 years after Voldemort's defeat. It is easiest to see if you pause the movie during Harry's conversation with Albus Severus. Several of the front shots of Harry show the scar.
Corrected entry: In the scene when Harry is at the edge of the Forest on his way to die, he tells Lupin he is sorry he will not be able to know his son. However, in Part 1, in the scene at the Dursley's house, Mad Eye interrupts Tonks and Lupin before they tell Harry that they will be having a baby - Harry never finds out about Lupin's son.
Correction: Just because it's not shown on camera, does not mean Lupin and Tonks did not later announced the news while Harry and the others were at the Weasleys' home, following Voldemort's attack and prior to the wedding. There was also ample opportunity for Lupin to have told Harry that he and Tonks had a son after meeting up with him again at Hogwarts for the big battle.
Corrected entry: When the school is assembled before Snape, as he announces that Harry Potter has been spotted, he says, "Earlier this evening, Harry Potter was sighted." However, outside the window behind him, it is light, while Harry, Ron and Hermione arrived in Hogsmede when it was dark.
Correction: So Snape is exaggerating, or reporting hearsay. People do this all the time. The important thing is that the students get his point, that Harry was known to be near Hogwarts.
Correction: Molly just used the same spell so it just looks the same.