To cover any such "events" I now have cameras fitted to both my bikes, front & back.
With a 256gb SD card they will "loop" record a full days ride before it starts to "overwrite".
Unfortunately (or fortunately) I have seen the benefits twice, so feel the expense was worth every penny.
Once a van pulled out in front of me and knocked me off, the second time the bike was knocked over on a filling station forecourt.
Both times the other party admitted liability immediately but if necessary I could have proved their culpability.