What is the ruling on the imam's insistence on adding to the prayer after the worshippers have alerted him, and what should the worshippers do?

It is obligatory for the congregants to alert their imam if he makes a mistake in his prayer, by saying "Subhan Allah" (Glory be to Allah) for men and clapping for women. The imam must refer to their alert if he is not certain of the correctness of his action. However, if he is certain of his correctness and that they are mistaken, he may continue. Congregants who are certain of their imam's mistake should not follow him in error; rather, they should wait for him until they can conclude the prayer with him. If two or more people alert him, it is obligatory for the imam to refer to their statement, unless he is certain of his correctness.