Indeed then one will have to thing fast about ones options ( pray cameras made a plate capture ) or you can keep up / catch up to the other car, and then what do you do.
Trust me i dont mind being judge and jury, i actually feel my country sort of force me to do so some times, but things can also get out of hand pretty quick and if i go to a place with no handles on the inside of the door, i will have to terminate myself / make / force some one to do that, which in itself dont really bother me so much as im old and i am sure the best parts are behind me.
Police here are or can be flexible, so say you come home and surprise a burglar, and in the resulting action he fall down and up the stair in your house several times and get beaten up bad, that is what it is.
Regarding dashcam footage, well i think its up to myself how much of it i want to submit, at least i would never put myself in a situation where it would be otherwise, and thats why i always say " keep mum about your camera in case of a event"
If bad enough and in doubt you could discrete "disappear" the memory card of your camera.