As they say, you can't fool all of the people all of the time. It's simply not possible. Someone with special knowledge is going to be a much more critical reader of fiction in their knowledge domain. The amount and precision of medical information I would have to put into a short story about doctors in order to satisfy a medically-trained reader is far greater and more demanding than what I would have to put in to satisfy a general reader. On the other hand, there are a lot of doctors and nurses and med techs and so forth out there, so this is probably worth getting right.
Another example of this is a short story I read some years ago, possibly in a Writers of the Future volume. In it, the protagonist is time traveling, and flips through a series of historical vignettes. At one point, the arrive atop a yurt in Genghis Khan's horde, and climb down the central tent pole to take some action. This threw me out of the story, first of all because "yurt" is a Russian word, and to Mongolians, it's a "ger". Second of all, gers don't have a central tent pole. They have a pair of offset poles supporting a central ring. Why do I know this? Because I've spent time in Outer Mongolia, including visiting and sleeping in actual Mongolian gers. However, this is a knowledge domain that I share with about seven of the people who ever read that story.
One of the challenges of being a writer is knowing where to set that dial. When does reality trump realism? Sometimes the actual details really are less believable than the fictional details.
The example that had generated the conversation was that @madge707 was working on a story about a San Francisco police detective. In the SFPD, detectives are titled as "inspectors". Someone in her critique group at the conference was confused by this, not realizing this bit of San Francisco detail. So the question was, did she go for the reality, which was confusing, or the realism, which was erroneous. (Obviously, there are fairly simple ways to resolve this, it's just an example.)
I provided a similar example from living in Portland. While Portland has a police department, just like virtually every other city or town in the United States, the Portland police department is formally known as the Portland Police Bureau. (The fire department is the Portland Fire Bureau, etc.) I'm not even sure most people in Portland realize this. It's not prominently painted on the police cars or anything. Almost certainly no one outside Portland knows this unless they have special Portland knowledge. So, as I said to @madge707, if writing about crime in Portland, would it be confusing to refer to the Police Bureau, or the PPB? Because that would look odd to most American readers, who expect the term "Police Department".
A couple of days later, I'm reading Mark Teppo's excellent and gripping novel Lightbreaker [ Powells | BN ] (which I have since left on an airplane, forty pages from the end, grrr) and what do I find but a reference to the Portland Police Department, being used by a character who is a cop from the Seattle Police Department. The reference is in initial caps, i.e., the proper name, which is of course, not correct. Something the character in question would absolutely know better than to do, insofar as real life goes.
I cracked up hard.
Ah, the magic of synchronicity.