the disagreement with things experts say is legitimate when the facts you run across don't make full sense when you apply logic to them. Then you dig to see if the holes in logic are explained and how their are explained. When people who are opposed to the views of those experts have more logical arguments, that's when it's reasonable to believe them more than you believe the first experts. Then it's the duty of those experts to make more sense. When it's something that affects our life, they need to pass an exam in front of us to convince us. Not with technicalities, but with logic.