Continuity mistake: The sun as shown in the introduction is visible and rather bright slightly above the horizon. As the shot moves through the clouds (takes only a second or two) and focuses on the houses, the sun is now shielded by clouds and is moved down quite a bit. (00:00:35)
Continuity mistake: The Dursley house is shown in the opening shot, as Harry sits by his window. When Uncle Vernon places bars on Harry's bedroom window, the shrubbery directly below the ground window is completely different. (00:00:50 - 00:07:55)
Revealing mistake: When Harry is looking at the photo album Hagrid gave him in his bedroom, there is a clear reflection of the photos in the lenses of his glasses. A moment later in that scene, there is no reflection seen in the lenses, because there are no actual lenses in the frames. (00:01:00)
Plot hole: At the beginning of the movie, Hedwig rattles her cage, and Harry says apologetically, "I can't let you out, Hedwig; I'm not allowed to use magic outside of school." But he wouldn't have to use magic to let her out - the key is visible sticking out of the lock on the cage, so all he would have to do is turn the key. (00:01:10)
Continuity mistake: When Harry enters the kitchen, the cake/pudding Petunia is fussing over is lopsided and shorter than the one shown in the close-up, when Dudley tries to pick at it. There are subtle differences in the look of the cake/pudding in subsequent shots of it too. (00:01:30)
Continuity mistake: The pillow and blankets on Harry's bed not only change position in consecutive shots, the actual pillow changes drastically from the time Dobby jumps up and down on the bed, until Harry confronts him about the letters. (00:03:05 - 00:04:30)
Continuity mistake: The cork board, hanging over Harry's bed in the Dursley house, significantly changes its position on the wall, as seen when Harry sits on his bed to speak with Dobby. The location of the thumbtack pushed into the top point of the Gryffindor pennant, as well as the angle of the other point, also change throughout the scenes in Harry's bedroom. (00:03:10 - 00:04:45)
Continuity mistake: When Harry first encounters Dobby, as he walks toward the corner of the bed to bow to Harry, a single sock and other clothes are lying on the bed. In the next shot facing Harry, the sock and clothes on the bed have noticeably changed positions and the two long ends of the Gryffindor scarf that hang over the trunk is visible. When Dobby sobs, as he walks off the bed, only one short end of the Gryffindor scarf hangs over the trunk, and it also changes position in following shots. (00:03:10)
Other mistake: When Harry is talking to Dobby in his bedroom on Privet Drive, Dobby begins banging his head against the dresser to punish himself. If you look closely, you can see that there is a slight delay between the time that Dobby's computer-animated head appears to hit the dresser, the time you hear the thump, and the time when the drawer moves and the dresser shudders. (00:04:10)
Other mistake: In the beginning of the movie, when Dobby is hitting himself with the lamp, you can clearly see that the first swing stays a few inches from his head, but he still grunts and shakes his head in pain. (00:05:20)
Continuity mistake: When Dobby stands on Harry's desk, in the close-up he slams the lamp base into his head with the electrical cord coming out of the base to his right. Yet in the next close-up the cord comes out of the base directly in front of Dobby and is now wrapped around Dobby's neck. (00:05:25)
Revealing mistake: In Harry's bedroom, when Harry and Dobby grapple with the lamp, just as Harry says, "Give me the lamp!" Dobby's left hand is between both of Harry's hands gripping the lamp stem, but in the reflection we do not see Dobby's hand, or arm, as he moves about on the desk, nor do we see the fingers of his right hand which grips the base. In this shot what we do see in the reflection are Harry, his hands, the lamp base, stem, shade and cord. No Dobby. (00:05:30)
Continuity mistake: When Dobby comes out of Harry's closet, he has a CG sock on his ear which he throws towards the dresser. The CG sock is not on the floor in the following two shots, although it should be, when the dresser and floor area around it is shown as Dobby says, "Harry Potter musn't be angry with Dobby," as well as when Dobby yells, "No!" and runs out. (00:06:10)
Continuity mistake: In the shot where Dobby takes Harry's letters from his robe and tells him about why he hid them he is standing in front of the dresser, you can see that the drawers in the dresser are neatly closed (with the exception of the bottom one, which is only slightly open). However, in the next shot when Dobby runs out the door with Harry chasing after him you see the dresser again, and this time all the drawers are slightly open and uneven. (00:06:33)
Other mistake: While downstairs Vernon hears Hedwig's squawks, as well as Dobby and Harry's exchange in the bedroom upstairs, distracting enough for them all, including the Masons, to take note. The noise upstairs illicits a reaction from everyone, which Vernon explains is a noisy cat. Yet when Harry very noisily chases Dobby down the steps, Dobby slams into the wall and Harry lands with a loud thud (not remotely 'catlike'), Vernon, who stands on the other side of the shared wall, pleasantly continues his story to his rapt guests, who are also not distracted by the noise. To suggest that such loud noises coming from the hallway right beside them would not draw any reaction from anyone, Vernon and the Masons included, is preposterous. (00:06:45)
Continuity mistake: When Harry chases Dobby down the stairs at the Dursleys, they stop in the hallway and there is a telephone on the table beside Harry. In the next close-up, the phone and cord's position differ and when Harry rushes past Dobby, the position differs again. (00:06:50)
Continuity mistake: As Harry chases Dobby into the hallway, he lands behind Dobby with knees bent, his left hand and foot in front and his right hand and foot in back. The next shot he has not moved, but his stance is the opposite, left hand and foot in back and his right hand and foot in front. (00:06:55)
Continuity mistake: While standing in the Dursley's kitchen doorway, Dobby says, "Then Dobby must do it sir, for Harry Potter's own good." In the next shot as the cake/pudding floats away, the wine bottle on the counter is pointing towards the hallway. Yet when Harry stands by the kitchen watching the cake/pudding float towards Mrs. Mason, the wine caddy is turned and the bottle now points towards the kitchen wall. (00:07:15)
Continuity mistake: After Dobby drops the cake on the woman's head, Harry's Uncle Vernon says something like "I'm sorry you'll have to forgive my nephew, he's very disturbed," and if you look at his face he's furious. In the next shot, if you look behind Harry you'll see Uncle Vernon acting very casually, and it looks like it's the same scene as when he was telling the joke to his guests. (00:07:50)
Deliberate mistake: When bars are placed on Harry's windows, so he does not escape, it is apparent that his windows have complete leaded panes of glass. Yet when Harry is being rescued, Ron and Harry speak with each other, even in low voices, through his visibly closed windows. (00:08:00 - 00:09:00)
Answer: The joke goes like this, "A California business man, while in Japan for some business meetings and a few rounds of golf, arrived in Tokyo a day earlier than expected. Feeling lonely that evening, he employed the services of a beautiful young Japanese girl to be his companion for the evening. Although the Japanese girl spoke very little English and the businessman spoke no Japanese, their passion roared and in the heat of the moment she began yelling "Machigatta ana. Machigatta ana" Hearing this, the Californian believed he had pleased his female Japanese friend and soon afterwards went to sleep. The next day while playing golf with his Japanese business colleague, his Japanese partner holed his shot from 170 yards away. Wanting to impress his friend, the Californian began yelling, "Machigatta ana!" The Japanese business man turned to the Californian and with a confused look on his face asked, "What do you mean wrong hole?"