Really? If I buy a domain that refers to someone else's business and redirect it to a porn site, I would expect a complaint against me to be upheld - it's at least trademark infringement, if not some form of defamation. The fact there was work involved and the client didn't pay doesn't change that.
His parents were quite surprised when a sheriff's deputy came to their home in hopes of serving a lawsuit complaint.
I never heard how the lawsuit turned out but I expect the client would have lost.