Where are you getting that from? There is no RAW "hacked ownership" (aside from the extended hardware test).
The extended hardware test IS what I was referring to in "hacking ownership", in a colloquial sense of the usage of the word "hacking". As opposed to "hacking" as in using Brute Force/Hack on the Fly Matrix Actions.
3 marks aren't "the equivalent of ownership," it's actually just the maximum level of operating permissions that can be granted to other users. This highest level of permission allows other users to erase other people's marks, reboot / format, and jump in.
3 marks lets you do anything that can be done with the device. Owning the device lets you do anything that can be done with the device. Ergo, 3 marks is the same thing as owning the device. At least in a temporary sense; of course you don't generate OS on your own drek.
But that's all peripheral and maybe a mistake to have even invoked it as what I was really talking about is how Kill Code's Reckless Hacking interacts with using 16+ dice pool on your Gunnery skill to "recklessly hack" a gun turret and be able to make it shoot at drek, even if you're not a decker/technomancer by virtue of simply being able to swallow the -15 dice pool penalty.
Unless Kill Code has something else that wasn't mentioned (and again, I don't have the book yet so I wouldn't know), it appears the Control Override rules in SR5 Core will prevent you from just dropping 15 dice from your pool and make a turret spray autofire/suppressive fire at your matrix-ignorant whim. Reason being: in order to usurp control of a vehicle/drone/turret, you must assume control on the hierarchy
one level higher than the current control. In other words, if the turret is already remotely controlled, it doesn't matter how many marks you have (or are emulating having by taking a dice pool penalty via RH) you can't issue remote control commands to the turret. Control Override rules say you have to go higher than remote control, which is Jumping In. Which means we shouldn't have to worry about someone with 16+ gunnery dice just dropping 15 and using the remainder to make the opposition's turrets/drones/vehicles take shots at their own side.
I was asking if Kill Code has anything that's able to combine with RH to bypass the Control Override rule. And saying that if not: there's no worry about Mr 16 Gunnery Dice from making turrets/drones commit fratricide on the NPCs.
