How do you respond?

The scenario here wasn't that complicated, usually when I see something unjust I'll make a comment and it's never been this bad. So I was in this new group that I had approached and was doing great, near the bar I see this 6'5" black woman kind of nudge this asian kid away so she could order first (away from the bartender's sight so he didn't say anything). Since I'm facing towards the bar in my group, I say to the woman "You shouldn't cut infront of people like that, maybe you should let him [pointing to the guy] order first". At this point, all hell broke loose.

She cuts into the group and gets an inch away from the my face, uttering "Who the fuck do you think you are?" and from here the rant lasted a good 5-6 minutes jumping from "Stop me then motherfucker" to "Show me what you gonna do". I pretty much waited for her to finish (had I interrupted I felt it'd be a shouting match). Once she did finish, I almost said "Done, yet?" but I imagined I'd live through another 5 minutes so I just say "Don't cut infront of people, it's that simple." As expected, she went down the "Or what??? Or what???" route.

It doesn't get any worse, right?

Wrong. Her boyfriend (who's as tall as her and built like Laron Landry) approaches. He asks he what's going on, she explains, he asks me what "my fucking problem is" and I kind of "It doesn't matter anymore, this isn't going anywhere". He yells "Maybe it does matter motherfucker", to which his girlfriend grabs him, tells me to go fuck myself, and they both leave.

Entire group = stunned, awkward, totally ruining the interaction. I mean I know this is rare but I ask you guys:

1) Did I respond correctly? If yes, what could I have improved on?

2) Assuming I responded incorrectly (which is more likely), what would you suggest?