If those who perform the slaughter have corrupt beliefs, is their slaughtered meat permissible to eat?

The questioner : O Shaykh, if the majority of them have corrupt beliefs, and we have known from several individuals among them that their beliefs are corrupt, what is the ruling?

The Shaykh : Here, too, a very important issue arises: Do these people, whose beliefs are corrupt, exit the fold of Islam because of this corruption, or do they not? If they exit the fold of Islam, their slaughtered meat is not eaten; if they do not exit, their slaughtered meat is eaten. Based on the first possibility, if we say that the corruption of their beliefs causes them to exit Islam, we must look at whether our ruling that they have exited the fold of Islam is a correct ruling, or if it contains some exaggeration or extremism. Here, some research is necessary. If these people, whom we have described as having corrupt beliefs and that this corruption causes them to exit the religion of Islam, have been presented with the proof from the Book of Allah and the Sunnah of the Messenger of Allah (peace and blessings be upon him), then the previous statement applies: their slaughtered meat is not eaten. However, if we have not established the proof of Allah against them, they remain in their state of ignorance within the fold of Islam, the rulings of Muslims apply to them, and their account is with Allah, Lord of the Worlds, as long as we do not know that the proof of Allah has been established against them.
Is the answer clear?