i really don't mean this as a personal attack on you - but you know when you're at a company briefing and there is always one person that asks a really dumb question? And everybody just rolls their eyes because the question is just so stupid but the person (and it usually is the same person) likes to ask because they like the sound of their own voice?

It's kind of like how your thinking is coming over. 'There's always gotta be one' type thing. When the FA asks the question it's not a question that is to be interpreted to the n-th literal degree. And if you are gonna speak out with a question of 'how do i know?' then it's kind of a roll-eyes situation and if the FA needs to make an instant judgement about whether the person is suitable for the exit they'd probably just move the person. They don't have time to enter in to a debate about hypotheticals.

Again - this is not an attack on you - just explaining how, to me at least, the situation sounds.