Threatening requires…an actual threat. Just showing someone a gun is not a threat. I would challenge you to show me a law that says “showing someone a gun is a threat”. The laws I looked up said that threatening someone with a gun is a threat.

you can communicate a threat to shoot some one without ever having a gun on your possession. (Gran Torino comes to mind, even if that is fiction.) Here's the relevant text of Indiana Code Title 35. Criminal Law and Procedure § 35-45-2-1. :

Sec. 1. (a) A person who communicates a threat with the intent:

1. that another person engage in conduct against the other person's will;
2. that another person be placed in fear of retaliation for a prior lawful act;
3. [trimming this, it's not really relevant here. Basically saying you can't yell 'fire' in a theater, or similar.]

commits intimidation, a Class A misdemeanor.

making threats in general is Class A misdemeanor. there's conditions that can bump it to a class 6, or 5 felony (like, you're threatening to commit a felony- aka to shoot some one.)

it goes on to say:

c) "Threat" means an expression, by words or action, of an intention to:

1. unlawfully injure the person threatened or another person, or damage property;
   ...
   6) expose the person threatened to hatred, contempt, disgrace, or ridicule;
   ...

I've bolded the important bits, and trimmed out a few that were irrelevant or just too wordy and also irrelevant.

care to explain how calling attention to being armed, isn't on some level intended to shock or scare school kids? based on posture and what little context there was, it seems more reasonable to believe he wanted- consciously or otherwise- to scare and pressure these kids. And he used a firearm to do it.

you can use a device to intimidate without ever actually drawing or firing a weapon. on a geopolitical level, the entire premise of MAD is based on that. Simply opening his jacket was "using" in that sense. "I'm armed right now!! [SEE?]" there was absolutely zero reason, as far as legitimate policy arguments go, that flashing that pistol bolstered... and a reasonable belief, by members of this group, that he was indeed threatening them.

I am hard pressed to conceive of a scenario where the situation would be improved by such an announcement where simply drawing it would not also be a greater improvement.

Am I stretching things- a bit- ? probably. Will this guy get off because "i didn't mean it that way?" Absolutely. because he's rich(ish), white, and in a conservative stronghold that likes this sort bullshit. Does it mean he's not guilty? No... Does it mean it's okay to do? absolutely not.