I tend to agree. Did he tell the cops on the scene he couldn't remember what happened? If he was conscious, bet the rent they asked that question.
This was single car collision, which means there is a damn good reason that vehicle lost all control and rolled for hundreds of feet. Yet the cops didn't blood test and the driver says it's all a blank? Wow.
They HAD to take a blood draw at some point in his care. While he may have just been distracted or tired, he has a history of either alcohol or drug use.