OK, I haven’t personally seen this film but I remember the question being asked (at least) on one now-defunct forum, by a regular user (so I think the film does have a chance of being real and not a fruit of someones imagination).
I don’t remember most of the details, but the film (or TV show episode) deals with a number of people being in one room, most likely sitting on one table. One by one, they are leaving the room (possibly by voting or by choice of one of them) and protesting angrily whenever they are told to leave.
At the end, it turns out they were all actually on a lifeboat and that leaving the room/table meant they were left to die.
I THINK the user mentioned it is from the 70s, but I am not 100% sure.