However should you confront, detain or threaten the armed citizen, you'd be the individual violating the law & subject to arrest should that armed citizen request a complaint. Police departments in NH have had lawsuits filed against them for unlawful detainment & identifying citizens without cause. No citizen in NH is allowed to be detained or identified unless being arrested for a crime or cited for violation of the law. LEOs aren't allowed to query registration plates of vehicles for the intent of identifying citizens & NH is the only US state in which electronic registration plate readers are illegal. (101 Reasons to Move to New Hampshire | Free State Project) or (https://www.eff.org/deeplinks/2013/05/alpr)
We were once kids ourselves, many of us remember the boredom & anxiousness teens experience due to adolescence.
I don't support the verbal abuse that the citizen used toward LEOs, especially as they were leaving.
The guy was likely pissed off that LEOs didn't know the law & abused his rights, not to mention they were going to steal his weapon to punish him for catching them lying while being audio/video recorded. I'm not going to be too judgmental of either side because they were both feeling the effects of stress & it was the ignorant citizens that initiated the 911 call due to their ignoranr fear.
I suspect that we live in very different environments & that one of us enjoys a hell of a lot more liberty than the other. I catch myself scratching my head while wondering which police state you & other brainwashed people here live within that you're so conditioned to voluntarily waive your constitutionally & civilly guaranteed rights without giving it a second thought. You're likely wondering what type of redneck (no I'm not a redneck) that guy is for living as though he's entitled to exist free from abuse by agents of the state.
If some of you individuals could get the hell out of your police state environment for the summer or merely a month, maybe you'd recognize the level of liberty that's been stolen from you.