What is the ruling on a man throwing the small pillar on the assumption that he is throwing the large pillar on the Day of Sacrifice?

'Abd al-Malik: A man threw the pebbles at the small pillar instead of throwing them at the large pillar, and this was on the tenth day. His excuse for this was that he saw a group of people throwing at the small pillar, so he assumed it was the large pillar due to his ignorance. After a day, he was informed that he had made a mistake. What is required of him?

The Shaykh : He must make up for what was missed and throw the large pillar on the day he was reminded and informed.