The One With The Routine - S6-E10
Corrected entry: At the end of the episode, Ross and Monica complain because they didn't get to perform their routine on the platform (because it cut to midnight too quickly). But the director must have known exactly when the filming would end, so why would he have put Ross and Monica on the platform 10 seconds before the end of filming? It's not just that he wants them in the background for a few seconds or something, because he wanted them for the blooper show (not the final show) and they didn't get a chance to dance up there at all.
Correction: Quite simply, he wants them to stop bugging him about performing on the platform. They have been in his face all night long, doing dance moves that (in his eyes) are not good enough, so putting them there in the last few seconds shuts them up and gives them no base for later complaints, while the same maintaining the quality of the show by filming the platforms with decent dancers.
Twotall