The saboteur waited for Rupert on exile island. He spent his time waiting in writing false clues.

When other players showed up, he gave them helpful hints and honest clues and he convinced them that Rupert was not just a back-stabbing jerk, but also a heavy threat as a competitor. They believed him because they didn't remember his as a player and because he wore an official Survivor baseball cap.

They went back and told their alliances what they had been told.