Correct. The point being that there is a seemingly infinite set of things we don't know, yet despite this most profound state of ignorance we presume to assert that saving 5 is somehow 'better' than saving one.

The point at which you decide to pull that switch (with no deeper knowledge of the people involved than their count) is the point at which you become an active decisive participant in a process that will end life.

That's significant. Far more significant than some cheap pop-psychology conundrum.