A few years ago we flew home with the DC ( early teen) , DH sat with DS , I sat with DD .
I was beside the door , the Cabin Crew said I could sit there if I would open the door if we needed to disembark.
Course I said "Yes" (extra leg room, who wouldn't) but I did think "Does this actually happen ? For real?"
I suppose it must . It didn't on our flight (mercifully)