The Fatigues - S8-E6
Continuity mistake: At the start of the episode, Cynthia is drinking a glass of wine. While speaking near the end of the scene, she is holding the glass in her right hand and says, "You know, guides you in your career path." The next shot is of Jerry and instantly the glass has disappeared from her hand with her right hand resting on the table. You can also see the glass is closer to her left hand now.
Continuity mistake: The exterior of the video store in the episode looks different from the interior. From the inside, we see a neon "open" sign on the window and other writing, and also no exit sign on the door, all of which is contrary to the outside view of the store. (00:09:25)
Continuity mistake: When Morty's exercising first wakes Kramer up, his clock reads 5:30. Then in another shot, the clock reads 5:26. (00:10:05)
Continuity mistake: In the theater, before The Movie starts, Brodie has his right hand on the outside of the candy bag in one shot, and suddenly in the next shot his hand is reached into the interior of the bag. (00:07:20)
Continuity mistake: When George and Jerry are discussing Elaine's poor dancing, The Keys that are sitting on Jerry's kitchen counter inexplicably disappear between shots. (00:04:10)
The Fatigues - S8-E6
Continuity mistake: When Frank breaks open an egg in the close-up of the pan, we see there are more than half a dozen eggs in the carton. However, in a wideshot of the kitchen, the carton appears to have only about three eggs. (00:16:15)
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.