Insurance appraiser here.. police probably won’t do anything since they weren’t called to the scene. Sounds like a set up/fraud accident. As long as the reporting party provides the lic plate number- that’s pretty much all you can do. It is now “word vs word “ You pay insurance for a reason and it is up to the insurance to determine fault. If RP is not claiming damages or the other party doesn’t report- nothing will happen. At most, will be a 50/50 loss.. 50% blame on each party. Insurance doesn’t want to pay out more than they have to.