Mitt,
I don't know David, can you tell us more about him?
I only meet him a few months ago, and rode/hung out with him several times, so he wasn't a close friend, but one of those rare people that you wanted to be their friend after talking to them for 5 minutes. I even told my wife that after the first time I meet him.
He was 39, husband, father of 2, from small town Iowa, sold wine for a living, was a bass player in a local band, had lived in a Italy for a little while, drove a 5 series BMW wagon, and rode an '08 black speed triple. He had rode dirt bikes for 30+ years, and was a very competent rider, but I think only recently got on road bikes, due to his spirited riding style. That might have been a cause, I don't know all the details, and don't really want to. It makes me reflect though that our group should have mentioned our concerns with his riding style to him months ago, and I will do that in the future if there is a similar situation.
It sounded like a decreasing radius / speed (50>30>10mph) downhill curve, and he locked the brakes and low-sided coming into the 10mph apex and hit the guard rail.
I didn't start this thread for sympathy, I wasn't that close to him, but I wanted to remind everyone else here that they have loved ones, and ride within your limits at all times.
mitt