I have to disagree...
These men believe 100% in a concept...that concept is that they are God's channel of communication on earth. No matter how weird and wacky things get they firmly believe what they teach is inspired because deep down they believe they are chosen and will be in heaven.
A concept like that firmly planted in their minds and hearts means any thinking process as to what they produce in terms of doctrines etc is always right at the time and Jehoover will let more line accordingly.
They are not, on purpose, leading people in astray knowing that they are wrong. They just believe 100% that they are chosen and thus they cannot ever be wrong.
Read Don Cameron's book Captives to a Concept..it explains it so nicely just how that once concept means they are so blind.