-
Confirmed.
I suspect this off duty security guard had never been trained in any form of conflict management. He was probably pumped full of adrenaline and incapable of rational thought. Why the fuck do you need to carry a gun when collecting your kid from a training class. Nothing about his actions was right but then he's just a scared little man acting the hero. I've no doubt a fat useless cop waiting for his colleague's return from the doughnut shop would have acted in the same way. It's a classic example of only having a hammer so everything looks like a nail.
Constable_Savage-
Isn't it often more than that though? You like the idea of hitting nails, so you buy lots of different hammers and hammer-adjacent items, and then go looking for nails or nail-adjacent or anything that looks nail-like in the dark through squinted eyes, and then hit away as soon as the opportunity arises.
NotThamesWater
Because ACAB, @Constable_Savage will confirm this.
I think this is most of the USA, cops just get sponsored to do so.