Audio problem: After the manager of the Wichita Falls propane store & his son start feuding with Hank about the Dallas cowboys, they start singing the theme of the Sooners football team. Hank starts singing the cowboys theme and they all try to outsing each other. When they do you can see that the son's mouth doesn't match up with what he is shouting particularly as Hank is about to leave the store.
King of the Hill (1997)
1 mistake in Hank's Cowboy Movie
Starring: Brittany Murphy, Pamela Adlon, Mike Judge, Kathy Najimy, Johnny Hardwick
Dale Gribble: Boil up some Mountain Dew. It's gonna be a long night.
More trivia for King of the Hill
The Man Who Shot Kane Skretteberg - S2-E7
Question: When we first meet Kane Skretteberg, what is the song he and his band are playing in the garage? It is right before they start singing Funcenter over and over.
Answer: If you are talking about the "Thou shalt not do this, thou shalt not do that" song, I'm not sure if a song like that actually exists. Green Day, the guest voices on the episode, might have just been improvising to keep their appearance from being too obvious.