The youtube video is clearer:
It shows the oncoming car (blue car) striking the car immediately in front of the Tesla, at which point all of it's airbags deploy. They then struck the Tesla.
The driver in the oncoming car (blue car) appears not to have been buckled in as their arms are flailing outside the window as the car spins in the air and lands back on the road.
Glad someone was able to walk away from that cluster...