The Slicer - S9-E7
Continuity mistake: When Elaine is woken up by her neighbor's alarm she looks at her own bedside alarm clock and it shows 3.30 AM. In the next shot when she buries her face in her pillow and screams, that clock shows 3.29 AM. (00:00:50)
The Slicer - S9-E7
Continuity mistake: At the end of the episode, after George has successfully airbrushed himself out of Kruger's picture and reinserted an authentic picture of Kruger, Kruger picks up the picture and explains to George why he doesn't think the mole Kramer discovered in Kruger's cancer screening is anything to worry about. After George says "Whatever" and just before Kruger begins explaining the story behind the picture to George, he tilts the picture towards the camera and if you look closely you can see that George is still in the picture. (00:11:00 - 00:22:20)
The Slicer - S9-E7
Continuity mistake: The slice of meat Elaine is holding up is not swinging in one shot, but after a cut it is suddenly swinging, and after another cut it is swinging more. (00:07:30)
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.