I am rereading Summer Knight and came to the part where the Mind Fog was released into the supermarket and Harry calls the Fog illegal. Now that reminded me of Skin Game where Butters had the globes of Mind Fog. Butters was using them against Binder's goons but I'd bet this wasn't the first time he used them. If so could Butters be in violation of the Laws of Magic?
Dunno... *could* be, I guess (in violation offscreen, that is: Binders goons are *not* protected by the Laws, only mortals are); but I seriously doubt it!
I would bet Butters got a really-comprehensive briefing from Bob, and understood what does/doesn't violate the Laws. I expect he was pretty dam*ed careful about how he used his Batmagic (not wanting to be snicker-snacked by Warden-attention).
Bob would have been extra-careful to brief him, because warden-attention on
Butters would have all too likely resulted in warden-attention on
Butters/Dresden/DuMorne/Kemmler's infamous lab-assistant...
Last but
not at all least: Butters was being all "Incipient Knight of the Cross" at the time, so we have good evidence that he was being extraordinarily ethical and moral in every respect.