Congress dreamed up some weird criteria to determine copyright ownership, and no matter how wrong it is, it still the law. Unless it was a work for hire, which

Congress dreamed up some weird criteria to determine copyright ownership, and no matter how wrong it is, it still the law. Unless it was a work for hire, which it probably isn't under 17 U.S.C. §101 as there was neither employment nor anything in writing, the copyright belongs to the author. There are probably implied licenses, but that is definitely a question for a lawyer.