Questioner: A fasting person is rinsing his mouth out and accidentally drinks some of the water, what is the ruling on his fast?
Al-Albaani: His fast is correct, and in that [mistake of his] is aafiyah [for him]—it is but Allaah who has fed him and given him something to drink.
Questioner: Isn’t that about a person who forgot?
Al-Albaani: I know, and what’s the difference between someone who forgets … “Our Lord, do not impose blame upon us if we forget or make a mistake …” [Baqarah 2:286]
Al-Hudaa wan-Noor, 321.