Is a person excommunicated if he excuses a polytheist due to ignorance?

It is not permissible to be lenient in declaring a Muslim an apostate (takfir) or a sinner (tafsiq) unless there is a clear justification for it from the Qur’an and Sunnah, and after fulfilling the conditions for takfir and removing its impediments, such as the person not being ignorant or misinterpreting. This is because a Muslim's Islam does not cease except with certainty and after the establishment of proof against them. The saying, "Whoever does not declare a disbeliever (kafir) to be a disbeliever is himself a disbeliever," is not absolute. Rather, it refers to one who does not declare an original disbeliever to be a disbeliever—meaning one who adheres to a religion other than Islam—or one who validates the doctrine of people of misguidance who contradict what is known to be a necessary part of the religion, concerning whose disbelief the sacred texts and the consensus of the Ummah have provided clear evidence.