Interesting case. I think that having more exposure will be better for Wilkerson, in at least being able to pin the bulk of the liability on Varker. To be honest, I think in the long run Wilkerson will make out better than Varker - he can get a personal injury atty to sue Varker for the liability being pinned on him; I'm not sure about AZ's negligence laws but the decedent is going to bear a lot of liability for riding unbuckled with a drunk, underage driver. I'd be surprised if Wilkerson got more than 10-25% of the liability for the accident, but you *never* know which way a jury will go.
I found it somewhat ironic that the man says he saved his "daughters" from a drug-addicted mother, and earlier in the article he admits to smoking pot that day.