A lifetime ago I trained for decades in martial arts. Spurred on by lots of being bullied (aka getting my ass whipped daily as a younger child). I noticed early on that those who run their mouths the most are the biggest bullies. I'm not prone to letting people roll over on me like that guy you encountered. I would have tried to diffuse the situation very briefly and once that was not working would have went to my sure fire go to that almost always ends it with a bully.

"Are you going to keep running your mouth like a bitch, or are you a man who can back his shit up? If you're a bitch, gtf out of my way, got things to do." Backs them into a corner, although the bitch's might be prone to escalating once you're out of sight by vandalizing the car. Of course, then you just have the gf point out their house and return the favor tenfold so they get the picture.