Continuity mistake: When Hagrid stabs Professor Flitwick in the hand with his fork, the fork changes places slightly between the wide shot of them and the close-up of Flitwick's hand, even though the fork hadn't been removed yet.
Continuity mistake: When Harry takes a bath in the Prefects' bathroom, the robe behind him repeatedly changes position throughout the scene. (01:23:20)
Continuity mistake: When Harry's name has just come out of the Goblet, we see a shot of Hermione with Ron in the background. In this shot, Ron is looking up at Hermione. A second later from a different angle, Ron is looking down, then moves his head to glare in Harry's direction. Nobody can move that fast. (00:32:45)
Continuity mistake: When Harry is on the Hogwarts Express, it is apparent that his scar is missing or very much out of place. Then during the second task, when Harry is swimming, the same thing happens.
Continuity mistake: During breakfast in the Great Hall, after Harry dribbles on himself, he and Ron are seated right beside one another and likewise their plates. When Nigel brings the box, all of a sudden there is a huge gap between them and a convenient open space on the table to place the box. (01:05:05)
Continuity mistake: When the Horntail is out for Harry's blood, in the overhead shot, as he hangs on the window frame his sleeve is pulled up showing his bare arm. However, in the next close-up as he still grips the frame, his sleeve is tucked tightly into his glove. (01:00:50)
Continuity mistake: When Ron glares at Harry in the Great Hall, he is angry with him for getting his name into the Goblet, but his face has dramatically changed from the previous shot (where he is in the background, behind Hermione).
Continuity mistake: When Hermione is walking over to wake up Ron she places a candle on the table. When it cuts the candle has moved closer to the edge of the table.
Continuity mistake: Right before the third task, Igor Karkaroff puts his hands on Krum's shoulders. In the next shot, however, his hands are off his shoulders and he is standing a respectable distance away. This change continues throughout the rest of the scene.
Continuity mistake: At the Yule Ball, when Harry, Ron, Padma, Parvati, and eventually Hermione, are sitting at the table, Ron's awful dress robe is lying on the table behind him, and it changes position between shots. (01:17:00)
Continuity mistake: When Dumbledore walks into Harry's dormitory, joking about setting fire to the curtains, the position of the clothing, etc., on Harry's bed differs between shots. (02:14:20)
Continuity mistake: When Ron enters the common room, Harry places himself at the edge of the couch. When it cuts, he has moved further in on it.
Continuity mistake: During the Tournament's first task, Harry runs behind the large rock formation to hide from the Horntail. After he's summoned the Firebolt, as he's crouched down, there is a semi close-up of Harry, then it cuts to a close-up, and the position of his red and black hood on his shoulders noticeably changes between these shots.
Continuity mistake: After Harry overhears the conversation between Snape and Karkaroff, Snape holds up the small glass bottle of Veritaserum while he accuses Harry of stealing from his store of ingredients. The way Snape holds the bottle repeatedly differs between the close-ups facing Harry and close-ups facing Snape.
Continuity mistake: In the cemetery, when Harry stands trapped at the statue, the ripped sleeve and arm cut are visible as his hands grasp the sickle handle, and they both differ between shots.
Continuity mistake: As the Horntail nears during the challenge, when Harry clings to the window frame, the characteristics of the broken windowsill he stands on changes depending on camera angle. (Not due to more breakage.) (01:00:50)
Continuity mistake: When Filch fires off the cannon for Cedric to go face his dragon in the first task, you see Karkaroff standing on Krum's left (viewer's right). In the next shot, the close-up of Cedric, Karkaroff is now on Krum's other side. (00:55:05)
Continuity mistake: At the Yule Ball, Hermione's hair is done up with the long curl at the back, and at times that long curl is either in front of her shoulders or at her back depending on camera angle. Additionally, even when her hair is normal, it changes in some consecutive shots throughout the film. (01:18:35)
Continuity mistake: When Harry is with Neville at the lake, Hermione, Ron and Ginny walk over. Then, as Hermione approaches Harry, her striped scarf noticeably changes position around her neck in consecutive shots.
Continuity mistake: In the Triwizard champions' tent, after Fleur picks her dragon, in the overhead shot Fleur looks up as Madame Maxime stands directly behind her, with her hands on the champion's shoulders. However, in the next shot Madame Maxime leans over as she stands toward Fleur's left, and her hands are off the shoulders.
Answer: Not at all. In fact, David Heyman made the decision for his eyes to be blue in the films for him to be more scary! They felt that his red eyes in Sorcerer's Stone did not show enough emotion to make him an evil character. It was felt in Goblet of Fire that the light blue eyes would be perfect to show his evil in the moonlight, and they kept it on for later films.