Call the popo and report the accident if you haven't already, serve the papers, name and shame, get things rolling man.
Do it before the end of the day.
If you have a lawyer get some serious sounding stuff with their letterhead sent, or make up your own (but I'm not sure about any hot water that could land you in, so research that first lol).
Get it done today, give him till Monday to act. He (hopefully) will be shitting bricks all weekend and there won't be many places open he can consult for advice.
Basically now you're wanting to 'bully' him into doing the right thing and sorting it out via insurance, if not, small claims or whatever with extra claims for lost wages (due to loss of transport), emotional damage, medical expenses etc etc (if you can do that. I'm not schooled up on all that myself)
Put as big a figure on there as you can without going too overboard. You want him to realize things are going to go from bad to a whole lot worse if he doesn't just pay his excess and have insurance sort it for him.
One thing that riles me is people who can't sort out their mistakes in situations like this, especially since he is insured so just has to pay excess and (according to the fact you have witnesses) was completely in the wrong.
Have no sympathy or mercy with the wanker.
Also if you haven't already you want to be getting written statements from the witnesses (I think emails are possibly legit?)
If you have a google you'll find heaps of info on this sort of situation I'm sure.
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