Call it a case of seller’s remorse. After a consignor successfully sold an Old Master painting at Christie’s for a considerable profit at auction last year, she had an abrupt change of heart, touching off a legal dispute that entangled not only the auction house, but also the work’s celebrity buyer: tech billionaire Sean Parker, the founder of Napster and first president of Facebook.

In this case, it would appear, the devil is not in the details. Parker acquired the painting, Peter Paul Rubens’s A Satyr holding a Basket of Grapes and Quinces with a Nymph (1620), on behalf of his charitable foundation in 2018. The consignor, San Diego collector Debra Turner, has provided no reason for seeking to renege on the sale. And as anyone who has seen The Social Network would attest, Parker (played by Justin Timberlake in the movie and, in real life, the owner of works by Ai Weiwei and other artists) is a formidable foe.

Amid the deadlock, as stipulated by the consignment contract, Christie’s proceeded with arbitration, presumably the best way to avoid alienating the powerful, wealthy clients on either side of the transaction. (It was also the best way to keep the dispute out of the headlines—at least, until Christie’s had to file paperwork last month to have the arbitrator’s decision held up by the courts.)

Peter Paul Rubens, A Satyr holding a Basket of Grapes and Quinces with a Nymph (1620).

In a statement, a Christie’s representative said: “A consignor sought to cancel a completed auction sale and following repeated attempts to settle the matter amicably, the matter was submitted to arbitration. The arbitrator ruled that Christie’s complied with its contractual obligations and that the successful bidder had lawfully acquired the painting. Christie’s is now seeking to confirm the arbitration award in federal court to conclude this matter, and transfer the painting to the buyer and the significant sale proceeds to the consignor.”

Turner consigned the painting at the center of the battle, a dramatic chiaroscuro-style work made in Antwerp, in early 2018. She and her longtime partner, property developer Conrad Prebys, had bought the work three years earlier, in a private sale, for $3.72 million, according to court documents. (After Prebys died in 2016, Turner separately sued the directors of his eponymous foundation, in part over their decision to award $15 million to his son, Eric, who had been cut out of his will.)

Turner, who represented herself without the aid of an attorney in the Christie’s arbitration, was not immediately available for comment.

When Turner first consigned the work to Christie’s, the auction house gave the painting a pre-sale estimate of $5 million to $7 million. The reserve, the undisclosed minimum price that the work must reach in order to sell, was set at $5 million, according to the court documents. The consignment agreement included a provision that the work could not be withdrawn by the seller once the deal was signed.

At the Old Masters evening sale in April 2018, Parker won the work for a hammer price of $4.8 million. (The suit notes that Christie’s ponied up the additional $200,000 to get the price up to the reserve, in accordance with the contract.)

The foundation—which focuses on global public health, civic engagement, the arts, and life sciences—paid a final price of $5.7 million (including buyer’s premium) in full on May 2, 2018, and promptly began to arrange for delivery of the painting. But before long, Turner claimed that she had withdrawn the painting before the auction, despite the fact that she signed the sale contract prohibiting her from doing so.

After several unsuccessful mediation attempts and the production of thousands of pages of documents, the appointed arbitrator determined that the Parker Foundation was the rightful owner of the work. He ruled that Christie’s should ship the work to the foundation and turn over the sale proceeds ($4.9 million after a two percent seller’s commission) to Turner.

Parker’s attorney declined to comment to Artnet News, but in a letter to the judge, he said the foundation supported the resolution.