premise: Dirty rugby players try to hold back the man with the ball. hypothesis: Batman, out of costume, attempts to sneak the time bomb past the Joker's sports-clad henchmen.
contradiction: Dirty rugby players who are trying to hold back the man with the ball are currently engaged in a sport and following some rules whereas Batman, out of costume, who tries to sneak the time bomb past Joker's henchmen is not playing a game, would not be described as a dirty rugby player, is not following set rules, and a time bomb is not a rugby ball.