Just to confirm the sheer stupidity theory:
No dash cams, but I was grateful for the Supermarket parking lot surveillance videos.
Dumb young lady backed into me at the legendary "high rate of speed" and despite my laying on the horn, she crunched me pretty good. I was very concerned about her accusing me of rear-ending her since there were no witnesses, but the surveillance tapes (according to the surveillance tape honcho) show clearly that she backed into me with my car being stationary.
Car was legally driveable, Iights, signals, hood latch all OK, and based on the "honcho's" e mail to me, her insurance company accepted liability and I got a fair adjustment from them. A little more of a central hit and the air bag$ would have deployed. And no other witnesses besides the cameras. (WHEW !)
Terry