Is criticizing others in their absence, such as saying: "Why did so-and-so do that? It would have been better for him to do such-and-such... this is wrong," considered backbiting that necessitates leaving the gathering, even if people consider it normal speech?

The Prophet, peace and blessings be upon him, defined backbiting as "your mentioning about your brother what he dislikes." If what you say about him is true, then you have backbitten him; but if it is not true, then you have slandered him. Criticizing the opinions and actions of others can be backbiting if it is intended to belittle them, mock them, or ridicule them, whether by word, writing, symbol, or gesture. However, criticizing mistakes might not be backbiting if its purpose is to clarify the truth and warn against those mistakes, as in the words of a pious critic concerning the weak. Warning about mistakes should be done with the best expression and the gentlest اشاره, and without slandering anyone specifically. Rather, it should be done by clarifying the religious ruling, just as the Prophet, peace and blessings be upon him, used to say: "What is wrong with people who say such and such?" Thus, some criticism is backbiting and must be denounced, while some is not backbiting if it is a critique of mistakes with arguments, intended to warn against them.