In Pulp Fiction,
Butch the boxer fights another guy and accidentally kils him. The "deal" with Marcellus that he struck was to throw the fight in the 5th round. IIRC the fight ended in the 4th round with the opponent dying. Butch obviously planned to double-cross Marcellus to make money and split, but if the fight ended with a knock-out/death in the fourth round, how could Marcellus know that he was double-crossed by Butch, other than by Butch acting suspicious and trying to jump town?
So, how did Marcellus know he was double-crossed by Butch?