Were the actions of the First Imam and the Second Imam correct, and what is the view of the Maliki school on this matter?

An Imam's doubt concerning ablution (wudu') has two scenarios:

Either the doubt is about the essence of the ablution after a certain impurity (hadath mutayaqqan). In this case, he is considered to still be in a state of impurity, and it is permissible to appoint a successor (istikhlaf) in his place.

Or the doubt is about the occurrence of impurity after a certain ablution. This doubt is not considered by the majority of scholars, and he should continue his prayer. However, according to the Maliki school, doubt about impurity nullifies ablution unless it is a recurring (mustankah) doubt. But if he doubts it during prayer, he must continue with it. If his purity becomes evident, his prayer is valid; otherwise, he must repeat it alone, without the congregants. The successor Imam should have continued from where the first Imam left off. Interrupting the prayer and restarting it is not permissible except with a legitimate excuse.