I am not sure what laws you have regarding fault Vs no fault and insurance. Here it would actually be a bit assinine to drive off without stopping as you wouldn't be able to get your vehicle repaired without having done so.

Nope, you need stop no matter what but you do not need to call police if the vehicles are driveable. You exchange your information (license and registration) and then you can drive off. You simply report the incident to your insurance and have the damage assessed and approved for repair. If you have a witness all the better. It makes no sense someone would drive off unless they didn't care about repairing their vehicle.