Is a person burdened with sin if he hears someone speaking inappropriately about a scholar due to his opinion, and does not advise him for fear that the advice will not be accepted?

It is not permissible to remain in a gathering where a Muslim is being backbitten. Rather, one must advise the backbiter in an appropriate manner, and alert him to the impermissibility of backbiting, especially if it is accompanied by mockery, insinuation, or suspicion, citing the Almighty’s words: "The believers are nothing but brothers... and do not backbite each other." If he does not desist, then one must end the conversation or leave the gathering.