There isn't a single frame in the rearview video that shows the reg no. clearly. So we can't be 100% certain that we have got the reg no. right.
However, I think it probably is right and good enough to report the incident as, if we are correct, not only was he/she driving dangerously, they were also driving while uninsured and taxed - and these are the people who do cause accidents as they are driving without concern for other users.
http://www.manchestereveningnews.co.uk/news/greater-manchester-news/rochdale-142mph-death-crash-letter-9350135
http://www.gazettelive.co.uk/news/teesside-news/andrew-corfield-died-multiple-injuries-8130532
Often, as here, the one who walks away is the offender.
<rant off>