Well I don't know exactly what kind of AI/targetting method they use now, but it is definitely not consistent, which is fine since they are McGuyver'ed together in a post-apocalyptic setting afterall. And there is no internet for them to connect to a server-size AI targeting system, yet they can tell the difference between the player, their friends, and zombies, somehow. From a robotics point of view that level of effective functionality is already an extreme long shot, but works fine for now, and their fluctuation in accuracy helps make it more realistic, to me. Sometimes my turret will one-shot head pop a screamer, other times that same turret will empty half a clip trying to hit it. I am ok with that because to me it feels about right, even though the loss of ammo gives me sad face sometimes, it is fair, I think. It takes a lot more than a mere motion sensor to differentiate between different target types effectively, and as some of us surely know, if you step in front of a turret that is shooting at zombies then you will def get hit in the crossfire, they don't notice you and stop. Having that level of on-board recognition is not impossible, noticing the player from their friends from zombies, is not far-fetched these days, just very very uncommon since most people have become hooked on cloud services. If it were cloud based it wouldn't happen, obviously, since wi-fi and facebook wouldn't be a thing in the apocalypse.
I am curious though, what kind of targeting AI mixed with random-ness they have now, a true system would not miss, ever, would be head shots every time, so I am guessing you had to add in that inefficiency, it did not happen on it's own. Like what is your technique for that?