Occasionally when I am bored I wander around Goodreads to see who is reading what and what they think about it. The other day I was doing this and one common complaint I saw from reviewers was when the individual liked all aspects of the book except this one detail that the author got wrong. For example, the author might be writing a book with medical situations in it, and numerous complaints would be, "I love this book but as a medical student/doctor/nurse, the author got a lot of details wrong." I have seen the same complaints for battle situations, arms/armor, professions highlighted in books (I saw one complaint once that said, "As a glass blower, I really can't overlook how wrong this author got my profession.") and much more.
The truth of the matter is that a lot of authors have to do a lot of research before writing a book and yes, they may get some details wrong, especially if their real-life specialty isn't in whatever they are researching. For example, an author might be a computer repair man (as well as author) but they need to write a book with medical situations in it. They'll have to do a lot of research to properly do that, and yes, some details might be misunderstood and/or overlooked in the process.
One example of the "research process" that I saw on Twitter the other day was an author asking if anyone knows anything about fiddle acoustics (or something along those lines). I can almost promise you this author probably has never played a fiddle. They do research, they learn as much as they can for their books and sometimes they get it wrong and overlook details.
Does it bother you when an author doesn't get "it" 100% right or can you, for the most part, overlook it? Why/why not?