I don’t know what’s wrong with those NPCs, (maybe his viewcone is narrow, because it’s blocked by his phone?) but I do know what’s wrong with many of them.
Part of what’s wrong with the viewcones is how no matter what angle they see you, the suspicion bar rises at the same interval. Not only that, if you perform something illegal while on the edge of the viewcone, they still spot whatever you did with extreme clarity.
The big problem with it is their lock-on feature. All guards pay no attention to NPCs, while paying all of their attention to 47. If you aren’t in direct eyesight of them, they do their usual head-turning pattern. The moment you enter their field of view, their head fixates on 47, no matter what he’s doing. What makes it worse is how even after you exit their field of view, it takes a second or two for the “lock-on” to deactivate. It’s what makes quick kills through a room hard, because you always need to wait a second or two after you round a corner or close a door, for them to stop “looking” at you.
It’s probably a programing nightmare to coordinate the position of 47 relative to the NPC, and of any solid objects in between, as well as the action being performed and how much is visible (currently all of it: no matter if someone sees 47’s head or butt while dragging a body – but does not see the body – they still “see” the body being dragged. It can’t be easy to create the “realistic scenario” it should be.