The Ruling on a Follower Who Precedes the Imam by One or Two Pillars

Question:
If a follower precedes the imam by one or two pillars, does the prayer become invalid, even if it is by just one pillar?

Answer:
If the precedence is intentional, the prayer is invalid. However, if it is due to ignorance, he should return and follow the imam. If it is intentional, it is invalid. The apparent meaning of the hadith is invalidity. But if it is due to ignorance: he bowed before the imam without knowing, and then he was taught, so he follows him. Or he said the takbir for bowing before the imam, and then he was taught, so he follows him.
Q: Or if he was forgetful?
A: Or if he was forgetful, he is excused.
Q: The jurists say: if he precedes him by two pillars, is it required that he precedes him by two pillars?
A: I do not know of any evidence for that. The Prophet (peace and blessings be upon him) in the prayer of fear bowed and prostrated. He bowed with the entire group, then prostrated with the first group for two prostrations, then he stood up, and then they followed him. He preceded them by three: the prostration, the prostration, and the sitting between them, due to the excuse.