Well I got home and opened a beer, spoke to my Mum who told me not to worry about it, I was expecting police on my doorstep if they'd said I didn't stop and then worried because I'd just opened a beer. My friend who works in a garage doing insurance estimates said I have nothing to worry about, he told me to deny all knowledge that I did anything wrong and that the fact that there were no witnesses helps. It must have been me hitting him though, he couldn't hit me with his back end. So yeah, a fun weekend.