As an outsider to OC culture watching that video a few things occurred to me:
Firstly, I don't think OC would be for me, were it available, but that is just a personal choice.
It seems to me that the police a) did not know the law, b) were pretty in that guy's face: they weren't aggressive, but did start to play the authority card when the video'er raised a point they could not answer.
Bottom line is that the video'er knew the law, and the police did not. There were also the fallacies relied upon by the police: the logic that someone who lacks the appropriate licences/permits would openly carry a firearm for all to see in the first place.
At the end of the day, it seems that whilst it is law that OC is possible, the police have not been appropriately trained in how to manage it. After all, they've been previously trained to only expect a visible gun on a authorised person (LEO, Security, Military) or in a fire-fight.
They have seemingly not transitioned to OC thinking.
I think the video'er's remark about whether they would stop every car hit the mark: the police officer answered "no" unless there was a violation: precisely the opposite that was happening with the OC guy: no evident violation, but being effectively stopped all the same....
I think both sides of the OC fence need to be thoroughly educated as to what it means and represents.