Factual error: The Devils-Rangers game is at Madison Square Garden, but when the Devils score, a siren goes off. That would only occur in the event of a Rangers goal.
Factual error: In this episode, after accepting a free Armani suit from Kenny Bania, Bania insists that Jerry repay him by taking him to a nice restaurant. Jerry takes Bania to Mendy's, a Glatt kosher NYC deli. During the ordering process Bania suggests, "Oh, get the swordfish. Best swordfish in the city. The best, Jerry." Swordfish is considered an unkosher fish by Glatt kosher standards since it does not have scales, one of the essential criteria. It would therefore never be served at Mendy's.
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.