That guy taping with a camcorder is just as uncool as someone taping at a nude beach. He would not get away with that shit in any of the bay area ranges whatsoever unless he had explicit permission from anyone the camera was near. I was taking pictures for a website and it was made very clear that there would be no pictures of people.
I don't know what the problem is with those people in LA, but sooner than later we are going to hear about some smartass LEO or wannabe LEO getting hosed on the range for the shit they try to pull.
In NO PART of the code on assault weapons have I read about it being mandatory to keep the paperwork with the gun. The guns, owners' names and serial numbers are registered with DOJ and if they have the energy to book you in jail, they have the energy to run the numbers on the gun over the radio. Same reason they would not impound your car because they want to run the license plate through DMV.
At best it is harassment and at worst, false arrest. Oh, and taking the gun with no just cause is robbery under color of authority and I know the apropriate response to that one homie. Officer unfriendly gets a paid vacation to club fed or a trip to the morgue.
Out of respect for rangemasters, I would produce paperwork as I usually do keep it with the guns, but if someone does not clearly identify themselves as an LEO and is willing to leave some form of identification for follow up (business card or the information from a card) then I consider the "stop" illegitimate. Don't forget that a lot of these cops, especially the hispanics and blacks, have lots of criminal connections and use them to scope out people to get robbed. No, I am not making it up, the feds have been jailing LA cops like crazy for that very thing.
Vallejo PD got caught red handed and flat footed on this back in the 1980s by a guy I met. They had this MCgruff crime dog thing going on where you register all of the valuables in your house on a special file and then inform them of any times you are usually home and might be going on vacation. The idea being that the cops would then know to keep an extra eye on your house when you are not home. Well, that is exactly what they did. A few of them were selling copies of the files to local criminals in return for a piece of the take, and they had a taste for gun collections.
Those fucks thought it was cute to also broadcast over the radio information about who had registered assault weapons in their homes and at one point "leaked" the info to the local paper and of course, my house was robbed of registered guns. It was amazing how the thieves stopped looking when they stopped finding registered guns. The way I heard it, DOJ revamped their entire protocol for who gets gun registration information after that theft and a couple of others, all in Solano County.
One aspect of the AW law I just became aware of is the transport requirements are the same as for a handgun. That means locked cases with the ammo not in the same case as the gun. That is even if the gun is locked in the trunk of your car. I have not seen anyone cited for it, and I have never been busted or even approached about it since I was using soft cases for years, but the law is apparently on the books.
I also sent my paperwork in for the new batch of guns and have not heard from DOJ, but I kept copies of everything so I figure that is decent enough if it becomes an issue.