The Statue - S2-E6
Continuity mistake: In The Statue, George claims to have broken a statue that used to sit on his mantel. However, in season 6, episode 3, "The Pledge Drive," George states that he would be a completely different person if his parents had a mantel.
The Statue - S2-E6
Continuity mistake: Near the end of the episode, Kramer acts like a cop to get back The Statue. The door is almost completely closed. Just before he leaves, the door is suddenly open about one foot, even though it hasn't been touched yet.
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)
The Statue - S2-E6
Continuity mistake: When Kramer gathers the old clothes, shoes, hat from the cardboard box on Jerry's table, they keep changing position in his arms between shots. (00:04:30)
The Statue - S2-E6
Continuity mistake: The first time we see Ray, he kisses his fiancée's hand. Elaine in that shot is holding her papers, with the thicker black book closest to her chest. A couple of shots later when he bows to "Jerry, lord of the manor" the books in Elaine's arms have switched position. (00:05:50)
The Statue - S2-E6
Continuity mistake: George had enough of Ray's pawn shop story and jumps up calling him a thief. Watch the couple at the table; the woman, wearing a purple sweater, has her hand on the man's arm in the reaction shot, when nothing of the sort was happening in the wider angle. (00:15:30)
The Statue - S2-E6
Continuity mistake: During the scene at Monk's, Jerry bumps George on purpose making him spill some coffee. George is holding his cup in the right hand and the menu with the left. In the reverse shot you can see Jason Alexander put the cup down, held in his left hand. (00:14:20)
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.