Continuity mistake: In season 4, episode 5, Marty Funkhouser is speaking at his father's testimonial. During his speech, he says that his mother died 10 years ago. However this episode is based around Funkhouser's mother's sudden death despite the fact that Marty previously claimed that she died more than 10 years earlier.
Continuity mistake: This mistake really applies to two episodes in season 1. In The Bracelet, Larry is approached by a homeless man who thanks him for the Chicken L'Orange. As a result of this (and his unkempt appearance), the women at the jewelry store will not buzz him into the store. The mistake is that Larry doesn't give this man the Chicken L'Orange until the 7th episode, AAMCO. And it is not just that the episodes aired out of order. Because in the episodes between these two, there are references that show that this IS the correct order of this season. So this becomes a circular reference that can't possibly exist.
Other mistake: There are multiple mistakes with the bowling scene in the beginning of the episode. Firstly, Mary is shown finishing her game with a strike. After she strikes she goes back to the table where Ted, Larry, and his wife are sitting. The scores are shown and Ted and Larry say that Larry needs a spare to win. In the scores it shows that Mary's last shot was actually an 8 and not a strike that she had finished with. Secondly, Mary had finished with a 140. Larry's score shows that he has a 120 in the 9th frame, with a strike in his first shot of the 10th frame and a 7 on his second shot. Regardless of whether or not Larry completes his spare, he would not have won, as his max score could only be 140, so he would have tied Mary. And lastly, when Larry goes up to complete his spare which should have had 3 pins remaining, there is a full rack of pins and Larry gets a strike. After his shot it is implied he won the match, even though the scores showed that it was impossible for him to have won.
Continuity mistake: At the beginning of the episode after Mary takes her shot at the bowling alley, the shot shows the scores on the screen. It shows Larry is in the 10th frame, with a strike on his first shot and a 7 on his second, with only a spare conversion of 3 pins left. Larry then says he needs a spare to win. When he goes up to shoot, there is a full rack of pins and he gets a strike, instead of shooting at the 3 pins that should have been left for a spare conversion. Also, when bowling on 1 lane as a group, you bowl 1 frame at a time. After Mary shoots, Larry should have had a full 10th frame without any shots.
Continuity mistake: When Larry and Jeff are at the restaurant and the waiter's arm catches fire from lighting the flambé dessert, Larry puts it out by pouring water on his arm. The wide shot shows the flambé dessert is no longer on fire. But on the next wide shot, the dessert is on fire again.
Continuity mistake: Season 5, episode 1, "The Larry David Sandwich." After Larry's near-death experience, he's at a party talking to Jeff and drinking from a very small cup. At first Larry's fingers are in the handle, but when he actually starts complaining about how small the handle is his entire hand is cupped around the cup.
Plot hole: In the final episode of season 6, Larry tries to find the name and phone number of the woman he was talking to in the waiting room. The receptionist begins to list the names on the sign-in sheet until she reaches 'Paula'. Larry nods to this, however Paula never told him is name, nor was there ever an off-screen moment when she could have. She could have been any of the women the receptionist named.