Have you ever been in a verbal fight in public?

At the grocery store recently , this guy ran up to the deli because his number had already been called. He had been couple aisles over shopping while he was waiting and now said " Im 83!" But they were on the next few numbers. This other guy near me looks at him and goes "Why are you being an ass? "And the guy replied " I missed my number buddy..mind your business!"
So the other guy goes "Yeah I will take you on!"
And the late to the counter guy goes "Anytime old man"

I was getting nervous because I was standing right in between them. Thats when I slowly started to back away. Even if perhaps he could've waited..I wouldn't have spoken up to the guy trying to cut in. He made a mistake but it wasn't the end of the world. Have you ever spoken up to someone or had an argument with a stranger?