Imam forgets and says the Taslim subvocally

Q: The Imam (the one who leads congregational Prayer) of a Masjid (mosque) led us in the Zhuhr (Noon) Prayer one day. After he recited the final Tashahhud (a recitation in the sitting position in the second/last unit of Prayer), he forgot that he was the Imam and said the Taslim (salutation of peace ending the Prayer) to his right and left sides so quietly that nobody heard him. When he finished the second Taslim (to the left side) and before he got up, he remembered that he was the Imam, so he repeated the Taslim in a loud voice. We heard him then, so we said the Taslim after him, but we did not say it previously at the first time as we had not heard him. The Imam did not perform Sujud-ul-Sahw (Prostration of Forgetfulness) at that time. However, when the Ma’mums (people being led by an Imam in Prayer) left the Masjid, he performed Sujud-ul-Sahw alone. What is the ruling on his Salah (Prayer) and that of the Ma’mums? What should he do to clear his conscience, as he is very worried about it?

A: The Salah of the Imam and the Ma’mums is correct - In sha’a-Allah (if Allah wills) - because they all said the Taslim. Sujud-ul-Sahw is not obligatory in this case.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.