One thing for sure, any officer with any time on the job will have a reputation. Be it good, bad or otherwise. You see each other in the worst of times quite a bit of the time. As a result you can usually see any flaws that officer might have. You/they can't fake it all the time. We also see all the made up and or exaggerated claims of wrong doing all of the time. Accusations most often don't mean ditty to guys/gals co workers until proven. The very vast majority are never proven because they are BS. But. Every now and then one will slip by and fool us all. But it is rare. Sure the entire world will know about any LEO's misdeeds, mistakes or omissions because that craps sells. In reality even though you could fill a page with articles about officers screwing up, in reality it is still quite rare. The LEO vetting process works pretty darn well IMO.
As for the trooper in question here, if she admits or is found guilty She deserves some serious prison time. I doubt that you will find many if any officers that disagree.
What vetting process? You take a silly civil service test, an even sillier PT test, and then get asked some rote riduculous scenario based questions by a small board (if even that). I felt much more stressed and under the gun during my recent PhD qualifying exams then I ever did by any LEO hiring board. Unless you mean there is a way to weed people out of the job after they are really doing it and you can see the flaws as you put it. I don't think it has anything really to do with the LEO vetting process as it isn't any different then getting hired for any other job but that most people just aren't criminal d-bags like this former trooper. Most cops that I know are no better or no worse then anybody else they just do the job they were hired to do.