Legal Question in Personal Injury in Washington

If the other person is an adult, I think you are both going to share some responsibility for any damage that occurs. You are negligent for allowing them to operate your vehicle, KNOWING that they did not have the proper licensing, and they are responsible because they took on some risk when they chose to operate a bike they were not legally qualified to operate.

The insurance is a side issue, but arguably, you took on a risk allowing anyone, included licensed riders to operate the bike, when you allowed it to be operated without any insurance.

If the rider is not looking to sue you for injuries, I think you count yourself lucky and let this go. You may have lost a lot of money on the bike's damages, but that is a cheap education compared to the liability you may have if the rider was injured. Separately, if the rider is not injured and only your bike is busted, I think not many lawyers are going to take the case on for you unless you pay an hourly rate, and by the time you are done paying that rate, you will probably spend more than the bike was worth, so that even if you win, you get your bike fixed but you're out the legal fees.

Also, even if you win, you have to ask, "Can I collect on the judgment?" If that question cannot be answered "Yes, very easily because the rider has lots of assets and cash in the bank," then again, I'd advise you to take this as a painful expensive lesson but to let it go because pursuing it may make things worse.