Researchers/authors are human.
Humans make errors.
Thus Researchers/authors make errors (if we assume transitivity is given).
So, can we trust literature? Well, being an agnostic I tend to never blindly trust any statement. I found dozens of errors in the lectures I attended and made the experience that lecturers respond very different to criticism. There are some that feel attacked, or those that simply do not bother, but there are also those that will really think about your criticism and will correct you or themselves after having carefully checked the issue in question again.
I think, that a researcher's duty should be to allow and work with criticism as this will lead to an even better understanding of the topic for all involved sides. Also, your criticism shows interest which is actually a good thing and should be rated as such.
A good criticism should focus on the research itself and leave out personal-related stuff.
So my conclusion is, that you shouldn't just do nothing because of those strange unspoken rules society has built up to underline the higher status of academic people. Remaining silent for social fears is a bad thing that leads to a vicious cycle and harms research in my opinion. You should be free to question whenever you feel like it is necessary to question. Consider for yourself for when it makes sense to consume someone else's time. If you are not sure about your criticism, make some own research. If you are sure your criticism is right, if you ask me, for research itself this is the best one can do.