Before Buford Tannen shoots at Marty, he calls him Dude.
The Americanized take on Dandy may have been derived from Yankee Doodle Dandy."
The Real Reason Buford Tannen Calls Marty McFly "Dude" In Back To The Future Part III
Buford "Mad Dog" Tannen uses the seemingly modern word "Dude" in Back to the Future Part III, but this isn't the anachronism viewers might suspect.
