When The Experts Are Wrong

In the second chapter of Philosophy, Fearn looks at free will and fate. In it he raises the point that sometimes the specialists and experts in the field are not in fact the people you should be looking to for the answer. When a question has been satisfactorily answered beyond reasonable doubt, the smartest people will move on to other important problems. This leaves extremists and 'lesser minds'  LMs still banging away. 

The problem is that the world is so complex, how do you as a layperson tell? If the LMs create whole new sophisticated (but ultimately incorrect) arguments that require a certain amount of application to follow then pick apart, even the greater minds (GMs) may not be able to debate them on the points. This can be a trap for other smart people. I often think there are lots of smart people working on unimportant problems. 

The same can be said for some jobs and businesses. Once the incumbents have a vested interest in keeping an idea/business alive, it is only genuine intellectual curiosity and bravery that will push people to risk everything and branch out into new areas of value add. The LMs may just be comfortable GMs who can't be bothered. This would be ok if they didn't lead others up the garden path. The question is, what signs should you look for to make sure this doesn't happen to you?