Hi.
I am a licensed and registered web development company, as well I have also reviewed several cases for clients who ahd been in the same circumstance, Its very simply really, You just need to have a licensed company review what has been done, or what you were literraly given as far as web files, a notorized statement from a licensed U.S company in court will suffice.
The advise is free, but please also understand, you should always have a contract in hand when hiring, There are a lot of unscrupulous people out here that will completely take advantage of those that are very legit, It ceratinly makes it much harder fhor those of us that are. Best of luck to you truly. I hate to see events such as what you are going through.
Suzannah