The Implant - S4-E19
Continuity mistake: During the wake for Betsy's aunt, George puts snacks on his plate while talking to the reverend. He puts at least 6 pieces on his plate while the next shot of his plate shows only 2. (00:14:15)
The Implant - S4-E19
Continuity mistake: After George puts a couple of the snacks in his mouth, he takes a bite of the next one before Father Jessup says George is great comfort. In the next shot, the snack George is whole and no longer has a bite taken out of it.
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.