"Primary Cause"

To set the scene, a semi-truck is parked at the curb on a boulevard, one with multiple lanes in both directions. It is there illegally, blocking a bicycle lane, while the driver goes into a fast food place for breakfast. Along comes a person driving a car and slams into the rear of the truck. His car goes under the trailer of the semi, shearing off the top of the car and killing the driver. There is no evidence that the driver of the car ever touched his brakes before he was killed.

The police are citing the truck as "the primary cause of the accident."

That makes no sense to me. It was a clear day, on a straight stretch of road, with no hills. How did the driver not see a semi-truck? How does a parked, unoccupied semi-truck in plain view of oncoming traffic cause an accident? Police do not whether or not a cell phone was found in the car, by the way.

Certainly the truck driver was wrong, and certainly in parking where he did he created a hazard. I would not argue if the police cited his truck as a contributor to the accident. But the truck, an inanimate, stationary object, as the primary cause of the accident? If the driver of the car, who pretty obviously never saw the truck, had hit a tree, would the tree have been the "primary cause of the accident?"

If the other party does something illegal, that does not relieve me of responsibility for my own safety. If a car runs a red light, it is not okay for me to use that as license to run into him and blame him for the carnage; I still have the responsibility, morally and under the law, to avoid hitting him if possible. What are the police thinking here, claiming that a stationary truck is the "the primary cause of the accident?"