I, (Annoyed Grunt)-bot - S15-E9
Robot Rumble Announcer #2: And the winner is nature's greatest killing machine, man! [Audience boos.] Show me where in the rule book that it says a human can't be a robot.
Robot Rumble Announcer #1: Right here: Rule 1.
I, (Annoyed Grunt)-bot - S15-E9
Robot Rumble Announcer #1: There's no love lost between these emotionless devices.
Answer: I'm not sure if this is the one you're thinking of, but an episode of "Ray Bradbury Theatre," called "A Sound of Thunder," dealt with a similar matter: a group of hunters travel back in time to hunt dinosaurs, only to find things have changed when they get back because someone stepped on a butterfly.
Xofer