I think the episode you're talking about (a delay in time where the effects of a fight happened well after the fight) is Pete from season 8. It's a two-episode story. I love that scene--watching Rimmer flung back by an invisible punch makes me laugh so hard I nearly choke. The fight is over a time device that Killcrazy and another thug try to steal from Lister and Rimmer.
If you're looking to buy the video, I think they are split up, one episode on one video, and one on another. Good luck!