Why didnt you report this?
Yes, so why didn't you report to the police within 24 hours?
Ok. In that case there is a reasonable chance they could prosecute.
Come what may, this is a failing to stop and report.
What they may well do is summons for failing to stop and report and also for careless driving.
But if you offer to plead to careless driving in exchange for dropping the failing to stop and report that will probably be acceptable to them.
If they allow you to deal with this by just providing insurance details then that would be a very good deal.
Can I clarify anything for you?
I could do a phone call but not until tomorrow as I'm out of the uk until then.
You may not get legal aid but you can pay privately.
Generally speaking you are better off with representation although a barrister under public access will be much cheaper.
All the best.