If you're an adult then here's what you do in this situation... you have your female friend call the police and report an assault while you start taking down the names of witnesses. Then you inform Mr. Patterson that you have reported his actions to the authorities and they are on the way and you watch him and his posse scamper like rats.
I'm 6'6", 300 lbs and I was a bouncer in some pretty rough DC night clubs for 6 years... so I've been in plenty of fights and seen this exact situation unfold a thousands times (several of the clubs I worked in were frequented by both Redskins and Wizards players and I actually took part in throwing Brian Mitchell and Juwan Howard out one night).
The only way to "win" in this situation, even if you are a professional MMA fighter, is to do the right thing and get the authorities involved.There's nothing wrong with stepping in and preventing your female friend from further harm, but the minute you do anything to encourage further aggression you are putting yourself on the wrong side of the law.
It's not about being a "man" it's about being smart.
I'm reminded of the "Road House" scene where Swayze tricks a guy into leaving the club rather than fighting him.
True tough guys don't go looking for fights. Guys who are looking to prove they're tough guys are the ones who do.