Exactly. It's an attempt on the part of the questioner to mindfuck the other person (mainly for the amusement of the questioner).
Nobody really knows what they'll do in such situations until those situations actually happen, and then they respond, as you say, instinctively.
I really don't like it much when people talk about stuff like this just in order to demonstrate their mental cleverness and "win" the discussion, rather than because they actually believe in something meaningful. Who cares if they "win"? What difference could it possibly make to anything real? Will anyone care next year?
We all know perfectly well what right and wrong are in our hearts. It's dead simple most of the time. That's why young children have such a keen sense of injustice. They haven't become sophisticated enough yet to indulge in the sort of intellectual dishonesty that older people routinely do in order to sound clever and win arguments.