” .... who keeps their belt snugly around their waist at all times when they are seated? “
I am pretty sure that it is now the rule, on SW, to keep the belt on at all times. That is my experience anyway, at least on short flights. But, I should probably check to be sure. (And, this was a longer flight than I ever use to fly SW.)
They are encouraging that more and more due to the rare possibility of sudden turbulence which put a guy on the ceiling and the whole cabin topsy turvy a while back. Or this case - this poor woman was too close for the belt to save her, but it could have saved those nearby. Actually, I’m afraid her heroic plugging of the hole is what saved th flight.