Wraith: I recall reading earlier that they said he had 3 beers and 3 "girly shots" over the course of between 4-6 hours, and his friends said he seemed fine to drive home.
The thing is, it is possible to control your alcohol intake over a period of hours to stay under the legal limit. Even if alcohol wasn't a factor at all, Dunn was a thrill seeker, and loved to go fast in cars. He's wrecked NUMEROUS cars in his life, and flipped one before the Porsche. Overall, it's not shocking to see him die from this, but also, the person who was riding with him had to have known what Dunn was like, sober or not.
If he drank that much, then it was a factor. The question is whether or not it was a significant factor. Pretty much any alcohol in your system will affect the central nervous system, it's just that it's not much of a problem until it starts getting up there.
He may have been cool to drive had he not been driving so fast. Reaction times are more and more important the faster you go.