Continuity mistake: In the clip before Fry knocks Fox off the air, the one person says, "Could you repeat the last part? *pause, cut.*" When we later see it broadcast on Omicron Persi 8, it says, "Could you repeat that last, *cut*."
Continuity mistake: When the filming of the fake TV show begins, Fry says "Lights." and Bender dramatically opens his chest cabinet to display a large stage light. The camera cuts to Fry, who says "Camera one." and then the camera cuts back to Bender, whose chest is now closed again. There wasn't enough time to shut his chest between the shots and we would have heard it anyway, given the amount of noise the stage light gives off.
Answer: You are thinking about episode 20 of series 2 - "Anthology of Interest I". She technically never kills anyone, but in the episode she ask a "What if machine" (one of the Professor's inventions) what would happen if she was more impulsive. The machine then shows the more impulsive Leela killing off the Professor to get the money from his will and thereafter killing Hermes, Bender, Scruffy, Cubert, Nibler, Amy and Zoidberg to cover it up. Finally she does something really impulsive with Fry.
Andreas[DK]