Thanks everybody!
The ride leader gave me and the other guy props for waiting up with the guy who flatted, on the club forum. I was about to post a reply, but I changed it to an email directly to the ride leader. I suggested that we could split up into smaller groups already at the ride start who would all stop if somebody flatted, as we were bound to have more flats. There'a a lot of crap out there on the roads still, and some people are taking their road bikes out for the first time. Then that group could be a bit more self-sufficient if they didn't catch up.
He agreed, sorta, and had already thought of splitting the group up into max 10 people, but for traffic issues. He found it "very surprising" that this guy had flatted twice - which isn't really that surprising when you know that he didn't find the culprit changing the first flat 
Anyhoo. I'm already making a few friends. That's why I stopped, actually, I've chatted a bit with the guy who flatted and he's really friendly. Well - I'd like to stop for anyone. Good point about what kind of rider do you want to be.
And I AM going to make an effort to get to know my way around! I'll print out a pocketsize map to take with me, and try and study the route beforehand. Most days I won't have trouble keeping up, I think, but I could still easily take a wrong turn.
Thanks for the feedback!
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett