The farm they hide out at burned down in Grampa vs. Sexual Inadequacy (1994)(#6.10) yet it remains in the original run down state with no visible signs of it ever being on fire.
When Lisa is starting in front of Homer when he is selling the tomaco's,There is another Lisa in front of her.
When the Colonel shoots Homer in the arm at the end of the episode, he says, "Where are my manners?" And as he fires, his mouth can be seen still moving, but no words are heard. In the original broadcast, the closed captioning has him saying, "There you go, son." The line might have been cut at the last minute, but the closed captions remained the same. This often happened in those days of the show.