That's why I included the bit from the collision investigator saying that there were indications of him travelling at around 56mph prior to the crash. That's pretty quick; quick enough for a motorist to not notice that they're there while they're pulling out of a driveway. I only know bits of the story myself, although it does look like speed was a fairly large factor, more than the moving around traffic.
I don't know the road myself - but a quick street view, it looks like a 30mph residential road. If the lad was doing over 50 when he hit the car, then... victim of circumstances that he weighted against himself imo.