"If you miss... absolutely nothing will happen. But you'll still be a huge disappointment."
This is an immobile NPC that only appears in Tutorial Island. Three spawn per round and they can easily be one shot with the Newbie gun anywhere. There's nothing too much you should read into this.
Back when the apocalypse was a far cry, the Royal Marines set these up because they were largely inexpensive and people back then were inaccurate using a simple gun. These were re-used during the apocalypse for Bootcamp training when smart people realised that the experienced people were dying far too quickly and the newbies were gaining momentum in the revolution.
There is no need to aim for a headshot, they will die in one hit anywhere.
Despite the target being on the torso, the bullet can go anywhere for the same effect.