Season 1, Episode 22: The One with the Ick Factor

I watched this on the DVD (bought in Canada)

Near the beginning of the end credits (at 23:03 according to my player), when Ross is ushering everybody out to go to the hospital, before Chandler comes out, you could momentarily see an object move across the lower left part of the screen. No idea what it is though. Maybe a mic? Or someone's shoulder?