Hadith: They lead you in prayers. If they do well, then you will be rewarded; but if they make mistakes, then you will receive reward and the mistake will be theirs

عن أبي هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال: "يُصَلُّونَ لكم، فإن أصابوا فلكم، وإن أخطأوا فلكم وعليهم".
[صحيح] - [رواه البخاري]

Abu Hurayrah (may Allah be pleased with him) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) said: "They lead you in prayers. If they do well, then you will be rewarded; but if they make mistakes, then you will receive reward and the mistake will be theirs.”
[Authentic hadith] - [Narrated by Bukhari]

Explanation

The Prophet (may Allah's peace and blessings be upon him) said that when leaders and rulers lead the prayer correctly, both the leaders and those who follow them in prayer will be rewarded; but if they pray incorrectly, only the followers will be rewarded while the leaders will bear the sin of incorrect prayer. Even though the Hadīth is talking about state leaders, mosque leaders (Imāms) are included as well. They will be rewarded or punished as per the way they pray. In addition, the Hadīth indicates the obligation of observing patience with those in authority, even if they pray incorrectly or delay prayer. In such cases, one must not break with them, and one should delay the congregational prayer as they do. For this particular reason, the delay is justified so that one can join the congregational prayer. For the followers, it would be as if they prayed at the beginning of the designated time for prayer. However, the delay is allowable only if the allocated time for prayer does not expire. It is noteworthy to mention that breaking with the community of Muslims; and refusing to obey the instructions of those in authority, parting with them, instigating people against them, or spreading their shortcomings are all at odds with the religion of Islam.