I managed to track down the collision report on-line minus the supplements containing witness statements.
The last 7 pages contain the report, absent any witness statements. I suspect the missing witness statements may well clarify things as to why they reached the conclusions they did so quickly. As I have said, most collisions are not rocket science to figure out, and ALL fatals are tragic (and can have a lasting impact on the surviving parties) regardless of assigned fault.
http://documents.rpvca.gov/WebLink/D...84&page=1&cr=1
From what I have read elsewhere, the lawsuit was still in its initial phases as of October 2017 and the estate of the deceased is suing everyone from the state of California on down. Ultimately, I suspect a settlement from Mayflower may be forthcoming somewhere down the line.
I also found a couple of videos indicating that this route is a heck of an attractive ride for cyclists which could make for some unsafe situations if due care is not taken by the cyclists exceeding the speed limit, and drivers having to watch out for them.