I don’t know if you saw my other post (#40) to different Freeper, but retired cop turned conservative commentator John Cardillo posted a video of his Tahoe - same model year as the one in this incident - with a piece of paper placed in roughly the same spot in broad daylight. It is - for all practical purposes - impossible to see.
What drives me mad is I used to live in GA at a time when they didn’t have temporary tags. People would just drive on what were ‘dealer tags,’ which were vanity placards of the dealer that sold the car. I made the mistake of driving up to Cincinnati and was pulled over the exact same way; at night and at gun point by Ohio State Troopers. I complied with the directions of the officers - they backed me up, put handcuffs on me, the whole 9-yards - and after they reviewed my paperwork, we all had a good laugh.
But, they couldn’t see any tags and they presumed the car was stolen off the dealer lot, understandably.
Window tint is funny. I watched a video from a state trooper over a decade ago who would park his vehicle 90-degrees to the road and hit his brights. You could see right through the tint that otherwise (during the day) would be nearly impossible to see through clearly.
And you are right, the tag should be blatantly visible. Here in NM you can tint darker than many states (except in Bernalillo County, where Albuquerque is, they have more restrictive rules on tint than the rest of the state). During the daytime I see many vehicles with no tags and nothing apparent in the rear window. No one ever seems to get lit up for that here, though.
Many dealers here will put the temp paper tag on the rear license plate holder to comply. NM doesn't use front license plates.