Thomas Shey
Legend
If the group has been thrown in a pit from which there is no feasible means of escape and they have been left to die, "points of failure" are no longer a concern. It sounds to me like this is describing a campaign end state, not a problem to be overcome.
That one is pretty extreme, but there are a lot of lesser ones: a group without a lot of outdoor skills loses the trail their map shows (there are numerous ways this can happen, but a pretty common real world one is people leaving a trail to seek shelter from unexpected weather) and can't find it again (again, not an unknown event). At that point, while they theoretically still have options, they aren't set up for most of them to likely work.
It doesn't have to be a case where there's literally no more options, but just where the other options are low enough chance of success to be unlikely. It isn't technically a dead end, but neither will it likely get you anywhere.
Edit to add: I will agree that it is one situation where it's either forward or stop forever, but it must be built on a whole sequence of events and decisions that led to this point. If this ending isn't acceptable, it shouldn't have been allowed in the first place.
That's kind of the point in avoiding single points of failure. All fail-forward is is a method of doing that systematically.