What matters the most is how to prevent things like this to happening to us right?
Instead in investing big bucks on those dash cams with the black box stuff. Why not just mount a standard digicam on to the dash? Most digicams have that tripod thread mount thing, so with a little sonofabiching the tripod mount on to your car dash, you are good to go!!
Because you will run out of power and memory. Do you then stop by the side of the road to format your SD card or replace the battery? Also, It's one more thing to install and turn on every time you drive around (don't want to leave anything expensive mounted in sight).
A black box type of dash cam will get power from the vehicle, it will have loop recording to never run out of memory, and can probably be left in the car and wired to start recording automatically when the engine is turned on.