What is required of the ma'mum (those praying behind the imam) if the imam makes a mistake and refuses to prostrate for forgetfulness?

Question:
He says: Honorable Shaykh, may Allah grant you success. An imam made a mistake in his prayer and was reminded of it, but he did not prostrate for forgetfulness after the taslim. He was informed of the mistake but he insisted and did not prostrate. What is required of the ma'mum? Do they have to prostrate?

Answer:
Pay attention to the imam. Pay attention to the imam. The prostration after the taslim, if left out, does not invalidate the prayer. The prostration after the taslim does not invalidate the prayer. Yes.