Camron Rust wroteBy rule, it is a dribble the moment it leaves his hands, but we sometimes can't tell unless/until they touch the ball again.
"I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description, and perhaps I could never succeed in intelligibly doing so. But I know it when I see it."
I know it when I see it, and I'm not calling an illegal dribble violation until he touches the ball after it hits the floor.