From what I see, he never made any actual threats other than how he dressed and what he carried.

He didn't verbally say anything threatening. He didn't brandish his weapon at anyone. He just went to buy groceries while exercising both his 1st and 2nd Amendment rights.

But others chose to be scared of him.

If we go by intent, he was doing a social experiment, not attempting to threaten anyone. But if making other people feel threatened because they misread your intent is a crime, that is one heck of a slippery slope. That could make every redneck wearing a rebel flag t-shirt, every black man in a hoodie, and every frat boy trying to buy a girl a drink potentially a criminal, depending purely on the opinion of those who observe them.

I would think this will get pled down to a disturbing the peace charge and a stern lecture from a judge about how there are smart and dumb ways to exercise your Constitutional rights. But if he digs in his heels and fights it, I wonder if the ACLU and NRA will go to bat for him?