Good morning,
Sorry to hear about your accident.
I was knocked off if in what sounds like quite similar circumstances a little while back but in my case the car driver was genuinely sorry and I didn't bother following it up as it was a less severe hit than yours, just one ruined rear wheel.
As a youngster of 63 I am trying to persuade a few people that I know that it is time to hand in their driving licences but this is not going well. Their perception of what is going on when they are driving is so different to mine, for example the reversing/proximity sensors are beeping because they are so close to parked cars on the right as they can't percepulaise where the cars on the left are!
Whilst it is of course it is possible that it has been suggested to the driver that given his age it is in his best interest to say this, my experiences with these older drivers makes me think that it is quite possible that the guy who hit you believes what he is saying. In his mind
he has not driven onto a roundabout without giving way, he may not even has "seen" the roundaout and he thinks he was driving down a straight unbroken road.
This may be relevant as it could affect the way that you phrase communications with him.
Whilst generally I am quite relaxed about these things and accept them as just part of life, in this case I think that I too would want to follow it up even though I think I have a good grasp of what giving up driving means and why people are so reluctant to do so. All the other things that you can no longer do as they need to be driven to, maybe in the centre of a big city no car is no loss but in smaller towns and villages no car means isolation and boredom.
Even after quite a few months I still feel a bit uncomfortable on some big roundabouts where cars are approaching the roundabout at 30-40 mph at 5:30 in the morning so probably not expecting to see a cyclist, even though I have two 500 lumen front lights, one solid and one flashing as a "hint" that I am there. :-) There is one roundabout that I now get off for and use the pedestrian crossing, it to has cars approaching it at 40mph+ and I need to do a right turn (3 o'clock exit).
So that is an adaption after a crash, whether or not it is rational it has kept me riding.
Bye
Ian