No True Scotsman Fallacy

Following terrorist acts which are subsequently claimed by groups such as the Taliban, ISIS, Boko Haram, etc. there is an immediate debate as to whether these groups are representative of the "true Islam".

Western authorities (i.e The US State Department) often claim that no "true" adherent of Islam would commit these acts, and there is nothing within Islamic doctrine that would justify these acts.

Middle Eastern authorities (i.e. Al Azhar University, world renowned centre of Sunni Islamic learning) often cite
Islamic law concluding that some of these acts are permitted.

Does the "No True Scotsman Fallacy" apply here to either party to the debate?

Western authorities (i.e The US State Department) often claim that no "true" adherent of Islam would commit these acts

This is certainly a clear use of this fallacy. We know the terrorists are also saying that no "true" follower of Islam would allow infidels to live. Religious fundamentalists will claim that there is one "true" religion (not many interpretations of equal validity) and that they have the correct understanding.

One you decide that worshiping a supernatural creator-being for which there is no evidence is a reasonable position, you give up your right to criticize someone for worshiping a different supernatural creator-being for which there is no evidence. Religion is subjective. There is no objective truth in it. Besides, the fundamentalists have their canon on their side, whether Muslim, Jewish, or Christian.