I see stories like this posted all the time sans audio tape.
The police have a little problem in that they want to keep the public safe but are often not skilled enough to properly recognize threats. For example in this situation something that has been often brought up is that they could have been mass shooters. Number of mass shooters operating as a pair and open carrying nationwide in the US = zero to date. After a two minute chat it should have been 100% apparent that they were not a threat at all.
Perhaps I was lucky... during my LE training and when working with senior officers, I learned that there are times when taking a "soft approach" and learning what you can before
you decide to take enforcement action is the best way to deal with non-violent people.
Obviously LEOs do have a safety concern and it would be prudent to tell the O/C'ers to keep their hands away from their weapons "and we'll get along fine." 98% should understand that. The obstinate 2% who don't will learn why it's a good idea.¹
Anytime a LEO encounters someone doing "the unusual" that is not harming anyone or anything and they start citing statutes, case law or questioning under which statute they'll be charged, the immediate next question is "are you advocating or protesting something?" This usually gives them a chance to "impress" you with their knowledge (right or wrong) and disclose their purpose. If they claim they're "just exercising their rights" you can ask them to "enlighten" you. This can be an interesting and polite discourse. In some instances, the LEO can tell them either to go on their way OR inform them that some other statute applies²
[if it does] and give them a chance to "correct" their behavior.
Of course, for this to happen, the officer has to be comfortable enough that the people he's talking to are not attempting to either "catch him off guard" or "set him up" for some kind of legal action. And too many "activists" seem to go to great lengths in asking stupid, annoying or momentarily irrelevant questions, IMO. In the case at hand, the Asst. Chief opened himself and his department to some serious civil rights claims. I hope he feels silly sitting in an academy class with recruits learning the principles of the constitution.
¹ Face it - if you don't understand why, you shouldn't be carrying. If you understand and claim it's your right to do as you please by putting your hand on/near the gun, just remember the phrase "Life is tough when you're stupid".
² In some states, a city's muni code might cover having firearms around carnivals, county fairs and the like. Or it may be that guns are prohibited in city/county parks as part of the "parks & recreation" code or "health & safety" code.