What is the ruling on the prayer of one who prays in the mosque courtyard, following the imam without seeing him, and if the imam makes a mistake in the prayer, is the follower excused for their ignorance in continuing to follow the imam?

Following the Imam is valid even without seeing him, or by seeing someone who sees him, as long as it is possible to know his movements. As for the congregant preceding the Imam unintentionally in standing and bowing with him, the prayer is valid, because a congregant preceding the Imam by one pillar does not invalidate the prayer unless it is intentional, except if the pillar is the bowing (ruku'), in which case the bowing (rak'ah) becomes invalid. However, if he precedes him by two pillars, his prayer becomes invalid, except in cases of ignorance or forgetfulness, in which case the prayer is valid, and he repeats the bowing (rak'ah).