I don't remember if it has been mentioned, but there are numerous misspelled names in the recent Art Tatum biography published last fall. If the index creator had known jazz, he or she would have likely caught most of them. In house editors who know jazz at publishers seem to be rare these days.
Stuart Nicholson's books have also been full of spelling mistakes, especially his bio of Ella Fitzgerald.
Raymond Horricks' book had a real howler. He was starting a pice on someone born in Lynchburg, Virginia, then threw in "Home of Jack Daniels." I guess this British author's drink was scotch.