Knotts knew he had the looks of a guy who could play a perennial-loser to the max... and made it an art-form... he was a comic-artisan. There was another scene in “ ...Mr. Chicken” where the 'villain' says to him “You miserable, little pipsqueak... just who do you think you are?!!”
Knotts... shaking like a leaf stammers... “Drop dead... that's who!” and runs like hell!
He was legend.
Oh, man! I'm laughing so hard I'm crying, here.
What a loss.