What is the ruling on one who forgot to ensure that the pebbles fell into the pit when stoning?

Question:
She says: I went to perform the rites of Hajj last year. When I went to stone the Jamarat al-Aqabah on the Day of Sacrifice, I forgot to make sure the pebbles fell into the pit while I was stoning. Is there anything required of me?

Answer:
The pebbles must fall into the basin, the basin of the Jamarah. Yes. If they do not fall into the basin of the Jamarah, they do not suffice. It does not matter if they remain in the basin after falling in, or if they roll and fall out.
The important thing is that they pass over the basin. If they pass over the basin, they suffice. If she is certain that some pebbles did not fall into the basin, yes, then she must pay a fidyah (ransom payment). She must pay a fidyah, and if she slaughters a sheep in Makkah, she distributes it to the poor.
As for if she stoned the Jamarah and finished, and the doubt did not occur to her until after she finished and after she returned to her country, there is no effect of doubt after the completion of the act of worship. May Allah reward you with good.