[Phanx]

Not related to the bug, but:

      local Player = GetRaidRosterInfo(Index)
      print('>', Player, Player == nil)
      if Player and Player ~= '' then
        Player = Ambiguate(GetRaidRosterInfo(Index), 'none')

Why call GetRaidRosterInfo(Index) a second time on the last line, when you already called it and stored its value in the Player variable on the first line? Just do Player = Ambiguate(Player, 'none') there.