I don't need 100% trust in a stranger. As I pointed out earlier, I would be happy to bet you that 99.99% of people in the US that see a rifle being openly carried will not be shot by it.
It's easy not to be paranoid as f**k when you made it through 8th grade math.
And I'd argue, in today's political climate, that this behavior is anything but unusual. Did you miss the Guns Across America rallies in every state capitol with people open carrying rifles in public?
Guns used to be MORE common in the US per capita 60 years ago than they are now. You could walk to your corner hardware store and buy a rifle, no background check needed. You could mail order rifles straight to your home, no FFL intermediary. No cool down periods, no NICS, no NFA restrictions on cool shit. Kids would have marksmanship clubs, and nobody thought twice when someone had a rifle in their school locker. Guns haven't changed. Guns were deadly back then and they still are today, because...get this...the design purpose of a firearm is to be deadly. That was true 150 years ago and it's the same design principle today.
What has changed is society. Half have been conditioned with an irrational fear of an inanimate object, and many choose to project that fear onto the law abiding citizens who own them. Our culture has traded personal responsibility and instilling good core values with vast swaths of violent media and an entitlement mindset. We have young men who are angry at the world for not handing them their dreams on a silver platter, and choose to go out with a bang.