What are the actions that invalidate the Imam's prayer but not the congregant's prayer?

Scholars differed on the invalidation of the follower's prayer due to the invalidation of the Imam's prayer:

- They agreed that an accidental ritual impurity (hadath) befalling the Imam does not affect the prayer of the followers.

- They differed if he led them in prayer while in a state of major ritual impurity (janabah) and they found out after the prayer: The Shafi'is validated the followers' prayer, while the Hanafis invalidated it. The Malikis and Hanbalis differentiated between the Imam being aware of his janabah, in which case the prayer is invalidated, and his forgetting it, in which case it is valid.

- The reason for the difference: Is the validity of the follower's prayer linked to the validity of the Imam's prayer?

- The Malikis mentioned 12 cases in which the Imam's prayer is invalidated but not the follower's, including: the occurrence of ritual impurity or forgetting it, the Imam laughing inadvertently, the follower seeing impurity on his Imam, the Imam deviating from the Qibla while the follower intends to separate, and the Imam becoming insane or dying. It should be noted that these issues are not unanimously agreed upon among the Malikis.