        All of that could have been a figment of his imagination.  It was possible to believe that he had suffered some sort of mental breakdown on the island.  He knew it wasn’t a hallucination, since his camera had seen it, but it was surely possible that he had drawn the messages by scratching them with his shoe, then taken a photograph.  Unlikely—he wasn’t given to flights of fancy—but possible.  It wasn’t something that he could take to court, so to speak.