Wtf. Why did he change his answer to Carl Sagan regardless?
To make the highlight reel probably. No one would know this guy if he had actually won the game.
Interesting update: So, apparently, the show fucked up and had a typo on the screen displaying the clue in the studio, stating "His slang term..." instead of "This slang term...", which is what prompted him to change his answer like that. So they're inviting him to come back on the show to play again.