Homer's car is green in this episode, rather than the usual pink.
There is a hedge around the Flanders' yard in this episode, instead of a fence.
The Simpsons' carpet is pink in this episode.
Marge's necklace is white when Homer throws their wedding photo in the trash and she enters the room, but turns back to its normal red color when she picks it up.
The person at the front of the ticket queue (presumably a scalper), bought 30,000 tickets but there would be a limit to how many tickets one person could purchase.
Maude says that Rod and Todd aren't allowed sugar however if you don't eat enough sugar you will get Hypoglycaemia, which can cause death.
Ned gets disturbed by Homer breathing through his nose during prayer and Ned shouts "BREATH THROUGH YOUR DAMM MOUTH!!!" at him, but in the Season 8 episode "Hurricane Neddy", Ned mentions to the Lord that he doesn't swear.
Terminator 2: Judgment Day: When Homer chases the Flanders as they try to escape in their car, he holds the golf clubs the same way as the T-1000 had shaped its arms. This then leads to Homer using the clubs to grab ahold of the car in the same manner as the T-1000. The scene where Homer walks through the hedges is also similar to the scene where the T-1000 walks through a barred door.
Vertigo: The scene where Flanders is walking up the square staircase is a reference to the bell tower from the Hitchcock film Vertigo.
1966 University of Texas Shooting: When Flanders, during a dream sequence, begins to shoot citizens at random from the vantage point of a clock tower, he is mirroring the 1966 actions of real life mass shooter Charles Whitman.