Caught on dash cam rolling back accident rear end scam

The Honda driver in front at the lights rolls back a long way in to the car with the dash cam.

This driver in the car with the dash cam was extremely grateful that he had the evidence he needed to prove that he was not at fault and therefore protected from being blamed for this accident.

Honda civic Rolling back dash cam accident rear end scam?

As Eric Cheung the poster of the youtube video says "Lucky I did have this dashcam and is well worth otherwise I will be at fault"