Interesting video. I'd like to see more of the beginning to get an accurate picture of the events leading up to it.
Those guys are riding pretty recklessly (in car terms)
I would agree with the prior post and just let them pass, that usually works best.
It looks like one of the bikes cut off the car and then break checked him, causing the first stop. Which is why I want to see what happened prior.
Couple notes,
car nor going outrun the bike unless top end usually
Better to drive slow to stall more time for yourself until help arrives
Best to stay in moving traffic and not get blocked in
Don't let the bikes dictate the direction you going
As far as their riding style, I've watched my grandpa guys ride before, Harley-s and prefer their style of riding instead. Side by side, road guards, move as a pack, etc.