Oh, I'm so sorry, for you, the rider, his family, your family, the whole group. It does sound like one of those things that happens when a motorist is too familiar with the route and just does things reflexively, but who really knows other than the driver himself. Makes me think about a fast descent I was doing yesterday and thinking about how I might be in trouble if I had to take evasive action at that speed. Cyclist or motorist--none of us can afford to get too complacent.