I... I did the unthinkable.
I walked from Balota over to Elektro and then all the way back, picking up as much food and supplies as I possibly could. On the way back to Balota I went through the airfield again and bumped into a guy crouching over something. Naturally I snuck up on him to check if he was a threat, and... He was crouching over two magazines for the M4 you can usually find in this area, and picked up one. So, since I couldn't take the chance of him sneaking up and killing me now that I've enough food, drink and ammunition for my two guns to last me forever so... I shot him. In the head. From behind, at point blank range.
Turns out... He was unarmed except for an axe in his inventory. There was absolutely nothing he could've done to pose a threat to me, and I executed him for no reason over magazines. Empty ones at that.