This is as wild a situation I have ever heard. Scares the daylight out of me as how Tesla can be so easily fooled as they don't verify the authenticity of the documents with either DMV or the original owner. I think the suggestion to get the insurance company involved may be a good idea.. If the car has a loan then get the financing company/Lien holder involved. Both Insurance and Financing companies have an army of lawyers to take this up . Hope this helps...OP's car insurance agent might be a good resource in how to handle this case, documentation, and attorney referral.