"Retrospectoscope" is a common colloquial term in medicine. Basically, when a doctor criticizes someone for using a retrospectoscope, he's criticizing that person for being a Monday-morning quarterback who uses after-the-fact retrospection to invariably be correct. As they say, hindsight is 20/20, but being correct with the benefit of hindsight requires no brainpower. What riles doctors (or anyone else, for that matter, who is subjected to second-guessing) is that even an idiot can be right 100% of the time when looking at the past.
Historically, lawyers, insurance companies, and government bureaucrats love to second-guess doctors with the assistance of their trusty retrospectoscopes. Of course, if they were so smart they'd be the ones making the critical decisions in split-seconds instead of having the luxury to take days, weeks, months, or years to pore over every word in a contested medical record.
The author of this description was provoked to criticize nurses who'd used a retrospectoscope on him because anyone can be correct in retrospection. But what's the value in that? Zero.