Beavis and Butt-head vs. the Vending Machine - S4-E28
Other mistake: When Butt-head is purchasing the pork rinds from the vending machine, he notes that the selection for them is F2. When he is pressing the buttons to dispense them, he presses the F button twice, but never the 2 button. Somehow, the machine still dispenses the correct item.
Butt-head: Beavis, I told you I wasn't gonna let you touch the remote anymore. Now, give me that, buttknocker.
Beavis: No, way. And stop calling me buttknocker.
Butt-head: Give it here before I kick your buttknockering ass.
Beavis: Stop calling me that, Butt-head! Stop it.
Butt-head: Buttknocker.
Beavis: Shut up, Butt-head! Shut up! I'm gonna kill you, Butt-head! I swear to go God, I'm gonna kill you.
Butt-head: You and what other buttknocker?
Trivia: Mike Judge not only received complaints about "Beavis and Butthead", but also some death threats, including a poem about the writer wanting to kill him.