Update on my bad day:

I did get an email from the leader, checking to see if we were OK. I don't think he was aware of what happened. Someone told him we were going off on our own. He said he didn't recognize us when we saw the group on our way back. I find that hard to believe (the others in the group did), since we have Kuota bikes that are pretty distinctive looking and not common around here.
I am very stiff on one side of my neck (not the side I fell on), but the bruises and other rash are really not bad at all. I feel better moving around and would like to ride today, but I think Steve wants to take a day off. His elbow hurts, but is less swollen.
If I had been leading this ride I would have turned around and gone back when I realized that 2 people were not with the group. In fact, we have done that when a man got heat exhaustion and we found him puking on the side of the road.
Well, just another story to tell!