So drivers shouldn't be expected to keep alert for the unexpected? What do you suggest the rider should have done? Chosen a different road? Have a man with a red flag following him to alert other road users to his presence?

I assume that US cars are equipped with a lighting system designed to illuminate the road (and other traffic) ahead?

Your argument comes perilously close to saying that cyclists shouldn't ride where they are legally entitled to, simply because of the relatively rare occasions when a cyclist is rear-ended.