Mr. Herrera is facing Beavis as he asks Butt-head, "Senor Butt-head, como es Juan?"
The principal's office spells his name as McVicar. But in later episodes it's spelled McVicker.
Buenos Dias is misspelled as Buenas Dias on the Spanish class blackboard. No professional Spanish teacher would ever make this mistake.
Principal McVicar looks leaner then he normally does. Also when he speaks he doesn't stutter like he normally does and his voice sounds different.