The ruling on the one who joins the prayer late if the imam prostrates for forgetfulness after the closing salam

Question:
Honorable Shaykh, what does the ma'mum who joined the prayer late do if the imam prostrates for forgetfulness after the salam? Does he say the salam with him, or what does he do?

Answer:
Yes, he says the salam with him if he has not yet stood up for the rak'ah he missed. He says the salam with him, meaning he prostrates with him. He prostrates with him, but he does not say the salam. If the imam prostrates after the salam, the ma'mum does not say the salam with him. But if he prostrates, he prostrates with him. However, if the imam says the salam and stands up, thinking he is not prostrating and that the prostration for forgetfulness is not required of him, and then the imam prostrates before the ma'mum has completed his standing, he goes back and prostrates with him.
Note this: if he knows that the imam has a prostration for forgetfulness, he waits and prostrates with the imam, whether before the salam or after the salam. It is not permissible for him to turn around. If he does not know that the imam has a prostration for forgetfulness, he matches the imam. But if the imam prostrates before the one who joined late has firmly stood up, he bows and prostrates with the imam, then he completes the missed parts. But if he has firmly stood up, he continues and shortens the prostration for forgetfulness for him. Yes.