The paper is an interesting read, but people must remember that this theorem still does not distinguish between Free Will or Randomness. It merely says that if a property X, is exibhited by the scientist conducting the experiment, then X would be present in the particles too.
As regard to whether X, is Free Will or randomness, Conway does not know. He gave it the provocative title of ``Free Will'' out of his own free will, or randomness, or what have you
See this page and go to the last section entitled ``Questions,'' where Conway admits to this in a seminar at the University of Auckland.