Factual error: In the scene where the angry mob is attacking the Simpsons in the tree house, Grandpa Simpson is shown aiming a double-barrel shotgun, which he then pumps to ready it for firing. There's no such thing as a double-barrel pump-action shotgun. (00:36:20)
Factual error: Marge, Bart, Lisa, and Maggie Simpson take the train from Alaska to Seattle, Wash. (The train shown in Alaska, is the exact same one that arrives in Seattle). This is not possible as there is no train, (passenger or freight), that links Alaska to the southern 48 states, including Seattle, Wash. Homer Simpson does not take the train to the southern 48 states.
Answer: I believe the joke is supposed to be that the way Texans speak is a language all its own.
Damian Torres