Yes I did read it and yes I think the author is wrong.

One of the basic fundamentals of Islam is the 5 Pillars. Every Muslim adheres to them, this lot do not. They may call themselves Muslim but there's nothing Islamic about them apart from usurping the name to their own ends.

Did you read the Didier Francois link? There's more proof there when he states that they didn't even own a Qur'an!

Furthermore, look at the attacks in Istanbul, they attacked Muslims in peacetime and during the Holy month of Ramadan! No Muslim would do that. Also the vast majority of people they actually kill are peaceful Muslims, no Muslim would do that or even condone it. Regardless of what people think about Islam Muhammad's revelations were to set out a 'societal code' for wont of a better term, and these people don't adhere to any of those code or practices which would prohibit the behaviour of these groups. Basically, they're just not Muslims!