What is the ruling on declaring scholars to be in error?

Question : He says: When we find a disagreement among scholars, is it permissible for any person to say to a scholar, "You made a mistake in this issue," if his statement is not the stronger position?

Answer : Yes, there is no doubt that both correctness and error are subject to occurrence among scholars. A person may err at one time and be correct at another, and his correctness may be more than his error, and this is a matter of no doubt. Therefore, the Prophet (peace and blessings be upon him) said: It is inevitable. However, for one to say, "You made a mistake," in the presence of the learned scholar is a lack of proper conduct, without doubt. I mean, if a man asked a scholar for a ruling and the scholar said, "The ruling is such and such," and then the man said, "You made a mistake," that is your question.
But if he sees that he is in error, he says, for example, he brings up the point and says, "Honorable scholar, or O Shaykh, what do you say about the saying of the Messenger (peace and blessings be upon him), such and such?" With respect and proper conduct. So the issue is, without doubt, that the people who exercise independent legal reasoning are either what?
The people who exercise independent legal reasoning are either correct or in error, and there is no doubt in that. But for you to confront the scholar by saying, "You made a mistake," or the like, that is a lack of proper conduct. As for a person discussing another's statement with someone else.
A scholar, so here too, it is better not to say, "So-and-so made a mistake," but rather to say, "The stronger position is such and such," or "His statement is weak," out of respect for the people of knowledge, because the people of knowledge have a right over the people, just as the people have a right over the people of knowledge.