Continuity mistake: George sits in Elaine's spot and puts his wallet close to a glass of water and a used tissue. When he gets up in the next shot, the glass is further back on the table, past the small plate and closer to Elaine and Jerry. (00:05:40)
Continuity mistake: Elaine sits by Jerry to ask him permission to hold The Baby Shower at his place. Jerry is holding a morsel of food in his hand, gone at the first cut. (00:04:20)
Continuity mistake: Reminiscing about the incident with the performance artist, George says that she was aiming at him with the chocolate syrup "like she was putting out a fire." Notice Jerry has nothing in hand. Next shot and he's clenching a paper tissue. (00:02:40)
Continuity mistake: Kramer just gave Elaine the bench she wanted. The Apartment door is open. Cut to Jerry who says all salty "Well, goody for you!", and the door is closed. It is open again next time it is in frame. (00:17:40)
Continuity mistake: During his odd holistic visit, Tor puts both the middle finger on George's temples. New shot, and he is using 2 fingers. (00:14:40)
The Statue - S2-E6
Continuity mistake: Jerry is on the phone with Rava's boyfriend to ask him about The Statue. In the close-up he is holding the cordless in his left hand, but the same hand is on his hip when he is in the background with all the others crowding the landline to listen. (00:12:30)
Continuity mistake: When Jerry's neighbours are arguing in the corridor about sponge size, Harold is holding the tiny scourer in different ways between shot (in a different spot and with his fingers suddenly stretched out). (00:08:40)
Continuity mistake: At Monk's, Jerry points at the woman feeding corned beef hash to her baby. There's an angle with the camera roughly behind Jerry Seinfeld's shoulder; the continuity here is sloppy, with George having his hand down flat on the table instead of with the fingers laced together with the other, and he has his right leg crossed and not the left. Just few seconds later he asks Jerry if he remembers his friend from Detroit, and he is pointing his left index finger at Jerry across the table instead, again, of having his hands close together. (00:07:30)
Continuity mistake: During the scene with Donna and the wine bottle, besides continuity errors with cork and glasses position already mentioned in this page, the level of wine itself changes; Jerry poured wine to Donna, but her glass is empty in some shots, and before Kramer's arrival both are full, only to become empty in the last shot. (00:12:30 - 00:14:00)
Continuity mistake: George is talking about the phone call; when he says "I don't like to go too long before I ask them out", the waitress with the blue cardigan is passing behind him. At the cut, she's already to the other side of the counter. (00:02:05)
The Jacket - S2-E3
Continuity mistake: In the shot when Jerry points to Kramer where the ruined jacket is and he walks across the room to go check it out, the box of Ritz crackers is facing The Opposite direction than before, and in the following shot he is holding it in a different way too, by the top of the box instead of the bottom. (00:19:40)
The Jacket - S2-E3
Continuity mistake: Jerry powers out of George's grip on his arm to go to the bathroom. Notice Jason Alexander 's right arm; when he is awkwardly smiling at Elaine's dad all of a sudden the coat is entirely under it, while he had the elbow in the middle of it earlier. (00:12:30)
Continuity mistake: When Elaine tells George that Jerry must go to the funeral because he could have been the one who killed the old lady, Julia Louis-Dreyfus starts stirring the beverage. The spoon is gone at the cut, and at the following cut it is in her hand, which was free just a second before. Same later when George says that the dead don't care; she is holding it over the cup, but in the next shot it's suddenly inside the cup, hands off. (00:15:15)
Continuity mistake: During their casual talk about death and wasting your own life, George says he plans to continue wasting it. Cut, and both him and Elaine are in different poses than earlier, with Elaine licking the spoon and George with his fingertips by his mouth. In the majority of the conversation there are no such jumpcuts and continuity is kept. (00:14:45)
Continuity mistake: Jerry and his friends are eating, and Elaine opens defending The Pony Remark saying she was just having conversation. She gestures with both hands free, but then at the cut she asks Jerry about the game holding a teaspoon. (00:13:35)
Continuity mistake: Jerry called his parents back to tell them about Myra's dead. When his dad at the end of the scene says "You know what this funeral's gonna wind up costing me?" Barney Martin is leaning his head against his hand all of a sudden. (00:12:50)
Chosen answer: George does mention his brother in the episode "The Parking Space". They actually really never mention anything that contradicts the fact he had a brother though, it just isn't mentioned.