They had make a choice and instead of playing Rock, Paper, Scissors to choose, they choose with a variant of the game I never heard of before. It's called Rock, Paper, Scissors, Lizard, Spock
This game was invented because it seems like when you know someone well enough, 75-80% of any Rock-Paper-Scissors games you play with that person end up in a tie. Well, here is a slight variation that reduces that probability. (Note that for those of you who like to swing your fist back and forth and say, "Rock, Paper, Scissors, GO!", might want to continue to do that, replacing "Rock" with "One," "Paper" with "Two," and "Scissors" with "Three.") This version is also nice because it satisfies the Law of Fives.
Of course forming a Spock hand sign right after forming a fist and shaking it while yelling "Rock, Paper, Scissors, Lizard, Spock" is extremely hard. Many people can't form the Vulcan salute under normal conditions. Still its a wonderfully geeky game.