Has Billy Sol Hurok ever faced questioning?
Methinks you may mean "Billie Sol Estes" (1925-2013), a good friend and business supporter of LBJ, who was a conman and convicted fraudster.
Sol Hurok (1888-1974) was someone entirely different, a noted impresario, who is someone that brings talented but unknown musical artists, generally classical and similar performing arts, from elsewhere to perform in the impresario's country.