If a 10 year old takes up an AK-47 and points it at you what are you going to do? If a woman carrying a child sets a suspicious package down what're you gonna do? This isn't a "decision by the chain of command" outside of ROE for the AO. Everything else is on you.
If your answer is "call the chain of command" your entire unit is now dead. Congratulations. The variance in the decisions is due to the fact you can't make decisions by debating the internal psychology of the moron who may be trying to kill you. Innocent people will die. That's war. I'm getting downvoted to death here because it seems the posh liberals sitting at their desks don't understand what an actual life or death decision feels like. To be honest I'm not shocked. The toughest decision most people make is what to have for lunch and even that is enough to give the yuppies anxiety.