The ruling on one who forgets bowing and then remembers it while prostrating

Question:
A man prayed and forgot to bow in one of the rak'ahs, but he remembered it when he prostrated. What is required of him?

Answer:
He has to go back and bow, then prostrate twice, and then perform the prostration for forgetfulness. He has to stand up, say the takbir while bowing, then rise, then prostrate twice, and then complete... If he only remembered in the second rak'ah, the second rak'ah takes the place of the first, and the first is invalid, which is the one he left out... if he only remembered in the second.
As for if he remembered during the prostration, he has to go back, stand up, say the takbir while bowing, then rise, then prostrate until the end, and complete his prayer. He has to perform the prostration for forgetfulness after that, before the taslim, two prostrations, before the taslim.

Question: What if the ma'mum forgot?

Answer: The ma'mum goes back, bows, and catches up with his imam.