Other mistake: When Hank runs into the building to hide and lays down in the square of moonlight on the floor, he looks up at the window and a couple of clouds pass by. The clouds move too quickly, and when Hank is shown again, no shadows from the clouds move across him.
King of the Hill (1997)
1 other mistake in Yankee Hankee
Starring: Brittany Murphy, Pamela Adlon, Mike Judge, Kathy Najimy, Johnny Hardwick
It's Not Easy Being Green - S5-E16
Factual error: Boomhauer's car, Ms. Sally, has a Texas flag license plate on it. These plates were not issued until 1992, but Ms. Sally was driven into the quarry in the late 70's or early 80's.
Hank: Calm down, Boomhauer! I can't understand a word you're saying.
More trivia for King of the Hill
To Sirloin with Love - S13-E20
Question: What is Boomhower's occupation?
Answer: Jeffrey Boomhauer is a Texas Ranger as can be seen in the final episode at the end when he sets his wallet down, it flips open revealing a Texas Ranger badge.