The article implies the self driving feature may be a significant contributor.
Considering relatively few other brands have similar autonomous driving, and that autonomous driving technology is still very much in its infancy I'd wager just having a classification of accident currently unique to Tessla is enough to put it in the lead.
I enjoyed this interview. We learn that there's some things even he doesn't know, and also questioned, some behind the scenes head cannoning, and enough bait to keep us questioning what'll happen, but not enough to spoil anything of substance.