What is the ruling regarding the Maghrib prayer led by the imam for the worshippers, when he becomes certain after the prayer that he had not prayed Asr, and what is the ruling regarding the prayer of the worshippers behind him, and what is the correct action in such cases? And is the imam sinful if the worshippers do not repeat their prayer?

Scholars differed concerning the ruling on one who remembers a missed prayer while performing a current prayer. The Hanbalis held that the worshipper should continue and complete his prayer, then repeat it after making up the missed prayer. The Malikis held that he should interrupt the prayer, make up the missed prayer, and then return to the current prayer. Based on this, the prayer of the questioner and those praying behind him is valid.