I would be inclined to let the insurance company handle it. Nice guys finish last in the world of accidents. See what happens is they string you along with promises of money, but it never materializes. Then if you do want to make an accident claim the insurance companies want to know why it took you so long to report the accident. The stories of the accident change and before you realize it you were the one that backed into the car. Don't get involved with the people in the accident. Let the insurance company be the mean guys by making the guy responsible for his actions. I hope you did get the insurance information from the guy at the time of the accident so you can make the claim. If you have insurance on your moped call then too and let them know that you turned a claim in on their insurance, but may need them to fight for you. Two insurance companies working through an accident claim is usually better and faster then an individual and an insurance company.
The tape recorder in the pocket is a bad idea. If the person you're taping doesn't realize he's being taped it's illegal. By having a taped recording of the confession and trying to present it as evidence you just might find yourself on the receiving end of a law suit. These people aren't responsible for paying for your moped, their insurance company is. That's why we have insurance companies. Also, since the claim will probably be less then $1000 it won't effect his insurance rates, but then again that isn't your problem.
Always remember, nice guys finish last.
Lamborn's Miniature Engines