Insurance companies will typically pay out for 'hard to disprove' claims such as whiplash, etc. up to a certain amount in an attempt to avoid going to court. Driving into the back of another car is a golden opportunity for shitbags to make a few easy quid. This has been happening in Northern Ireland for years and, from this thread, it looks like the practice has spread to the mainland. I've heard of cars with just the driver in them being shunted and ending up with five personal injury claims against the person in the car behind. Work it out.
My attitude is what goes around comes around. Shrug your shoulders and get over it. Look on the bright side, the Supra wasn't damaged, you have insurance, the police seem to be reasonable and your conscience is clear. In this life it doesn't pay to be honest but, if it's any consolation, at least you're much better than thieving, lying pieces of s**t.