But he has additionally represented artists Takashi Murakami, James Turrell, and Roxy Paine when every sued their former dealers for breach of contract, and Christopher Williams in a case by which a fabricator sought ownership of Williams’s work. Doing business as ARTxLAW, John R. Cahill is a New York litigator and transactional lawyer of more than 30 years’ expertise, generally in non-public follow; he also served as general counsel for Phillips and chief commercial officer at Sotheby’s. He’s received multimillion-dollar judgments for purchasers like Sotheby’s, and represented John Howard and Martin and Sharleen Cohen in their lawsuits as part of …