Same thing happened to my boss years ago. A road rage incident. The aggressor followed him into a gas station, got out of his car screaming as he came at him. A quick point of the pump nozzle shut him up, and turned him right around.
“Lethal” weapon? Nope, Ethyl weapon!
Another lesson to learn. When approaching someone, do not hide your hands.
It is usually a few small missteps that lead to a bad outcome… Language barrier or not being understood (regional dialect, slang, poor enunciation, bad hearing - can happen to anyone), hands behind back, following too closely.
Great that you were aware and maintained your composure and no one was hurt.