We must understand that with the candidates everyone was assigned a number so the fact that Locke was one of "the numbers" could mean something. Not to mention he was dead long before Jacob died so he could have presumably crossd out Johns name but he didnt, not only that but ive read Burke was crossed out even though Juliet died hours after Jacob. My best guess is he knew she would die and crossed her off. Now of course JAcob knew Locke was dead but for some reason he didnt cross of his name. I always said I wouldnt give up on Locke resurecting until they bury him and I did give up.... for about 15 minutes. I also loved that Kate wasnt assigned even a candidate.