The gist is that in Bayesian terms, the fact that someone thought an issue was important enough to lie about is evidence that their claim is correct.
Or their position on the issue could be motivated by some other issue you don't even know is on their agenda.
Or...pretty much anything.
Abram Demski and Grognor
Much of rationality is pattern-matching. An article on lesswrong might point out a thing to look for. Noticing this thing changes your reasoning in some way. This essay is a list of things to look for. These things are all associated, but the reader should take care not to lump them together. Each dichotomy is distinct, and although the brain will tend to abstract them into some sort of yin/yang correlated mush, in reality they have a more complicated structure; some things may be similar, but if possible, try to focus on the complex interrelationships.