Visible crew/equipment: After Jerry, Elaine, George and Kramer walk out of the orange stairwell, there is a shot as they come out the door. A car drives past. The crew is reflected in the window.
Continuity mistake: In the first scene (approximately 3 minutes in) where Jerry points out the red-headed woman in The Parking Garage to George, she is leaving her vehicle in a section of the garage that is labeled 14 with a green background. However, later (approximately 23 minutes in) she is shown returning to her car in section 14, but the color is now yellow.
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.