From reading the article, it's not clear to me that the State Patrol had direct knowledge or actually required the pelvic exams until the first complaint was filed in 2015, and it may be a matter more on the doctor and his practices than the Patrol.
The time frame in dealing with it once a formal complaint was filed is troubling, but could just as easily be chalked up to institutional inertia, than any actual malfeasance.
However, I am decidedly suspicious that someone along the line, this Rice guy heading up the Patrol, or the Doctor himself, quietly decided that they could use pelvic and rectal exams on female candidates as a filter, or sort of hazing, trying to weed out any candidates who objected, refused, or otherwise showed too much distress at that portion of the exam to continue. Perhaps in some sort of misguided belief that the ones who could handle it would be better officers.