So, copyright it. End of problem. His list may be original, but it's probably not creative. Therefore, it cannot be copyrighted.
Contract law and trade secret law are the solutions for protecting his list.
I was under the impression that his list (the names he chose and the order in which he chose to format them) constituted an original work with some underlying creativity. However
this case seems to support your conclusion.
That's cool. IANAL.