This is the kind of moron for whom felony convictions and lifetime loss of RKBA were invented.
Sadly, I saw someone (not sure who or if they are a member of this list) over on the KSL comments board more or less defending him and open carry in context of this incident.
Unless the kids did a WHOLE LOT more than just ask a stupid question/joke about mustard, this guy needs to rot for a while.
I suppose it is possible--though hard to imagine at this point--that SOMETHING other than what is reported might have gone down that could have actually justified him pulling the gun (and then NOT reporting it right away).
But at this point, chalk him up to one of the 2 out of every 1,000 permit holders who does anything to lose a permit; and about 1 out of every 10,000 permit holders who actually commits a crime of violence with his gun.