Masbooq forgot he has to make up a rakat and makes salam

Question:

A person came late and missed a rakat with the Imam. When the Imam made salam, the masbooq forgot he has to make up a rakat, thus he makes salam too. Thereafter, he immediately realizes he is a masbooq, so he stands up and makes up a rakat, then performs sajdah sahw and completes his prayer. Was his action of his correct? Answer: ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﯿﻢ In the name of Allah, the Most Gracious, the Most Merciful

If the masbooq (latecomer) forgetfully makes salam with the Imam (i.e. he literally does the first salam at the same time as the Imam [which is very rare]), i.e. he makes salam with the Imam and stops on the meem of As-Salam with the Imam, then stands up immediately after remembering, or he makes salam before the Imam, then sajdah sahw will not be compulsory upon him. However, if the masbooq forgetfully makes salam after the Imam, then sajdah sahw will be compulsory. (Munyatul Musalli wa Ghunyatul Mubtadi: p. 161 [Maktaba Tayyiba]; Raddul Muhtar: v. 2, p. 350 [Maktaba Imdadia]; Fatawa Mahmudia: v. 10, p. 405-407 [Darul Isha’at]) Only Allah knows best

Written by Maulana Mohammad Ahsan Osmani Checked and approved by Mufti Mohammed Tosir Miah Darul Ifta Birmingham