I've had a pretty wild ride from being hit at probably less than that speed.

I'm sure you've seen video of the police performing a PIT maneuver. That's basically what happened to me--tapped by a car starting from a stop sign. They got a scrape, I got totaled. And, yes, it works as advertised--totally confusing, my foot somehow found the brake but I have no recall of doing so.

And all 4 Tesla occupants were injured. Something doesn't add up.

2-way stop and the other guy hit the Tesla at 40-60 no seatbelt?

That would track with the injuries in the Tesla as well.

Gotta come up with the energy somehow. If the Tesla doesn't have it the other car needs to.

possible if it accelerated after crashing