Yea that is unfortunate but i've been on many group rides with people i don't know, the risk level is ussually higher and i ride really defensively at first untill you get to know people. That being said there is no excuse for the way this person (and his "friend" for that matter) acted. Being relatively new to this forum (not riding) myself it just blows my mind someone would do that. Id like to hear what he has to say as well
Forum-> <- that guy