Cyclist drifted left into path of passing motorist as he was looking back.
Oregonian story: "[The cyclist], riding second in the single-file line, signaled for a left turn, drifting left as he prepared to turn. "
Rider Michael comment: " I was looking at his face and bike as the car hit him. "
It is generally considered acceptable to cross over double yellows in order to pass cyclists when there is no oncoming traffic even though in most states it is technically illegal. In some states, though not in Oregon, it is explicitly legal to do so.