Apparently it was a big group ride and the stopped guy was blocking traffic on the left. There was also a guy on the right side blocking traffic.
I understand and agree if you hit someone from behind it's automatically your fault, but I'm curious if there's a scenario where you'd be off the hook. With bikes weaving around to avoid the stopped guy it could be very hard to tell what's in front of you.
I'm not a fan of group rides like this, one goes down and it's like a domino effect.