Just because somebody was once a cop or served in the military does not necessarily make them knowledgable about ANYTHING.
And I say that from the perspective of a police firearms instructor (almost 32 years) who was in law enforcement related positions in the National Guard for 20 years. I've seen this from both the police side and the military side.
Most people, in any endeavor in life, coast along and do the minimum (or a little more) necessary to function in their occupation.
Only a small group of motivated people devotes any of their own time to improving their knowledge and abilities and skills.
Only a small group of motivated people even pays attention to THEIR OWN EXPERIENCE and learns from it. Most people just bumble along in the fog.
People who lack intellectual curiosity irritate me, and the older I get the more it irritates me . . .
So, if somebody was a cop, or in a military specialty where they were armed as part of their job function (infantry, MP, combat engineer, etc) they had the OPPERTUNITY to learn things, but only if they PAID ATTENTION!
And most likely, if they ARE knowledgable, it's because they had a personal interest that aligned with their job function, and they took it upon themselves to learn more, because it was fun for them. That's NOT most people, unfortunately
You can only learn from experience if you pay attention!