The auction house is Sotheby’s and the sellers have big questions. “The traders asked Sotheby’s, according to court papers, whether it had been aware that there was a much higher price to be had for the painting. Hadn’t Sotheby’s taken the painting, presale, to an apartment where the Russian billionaire had viewed it? Were the traders misled to favor the Swiss dealer, a valued Sotheby’s client named Yves Bouvier?”