Say what you want about the idea of Superman being a stone-cold killer in Man Of Steel, but he had no choice but to kill Zod (and it's not like it was an entirely unprecedented action for the character). What was less acceptable, for some cynics at least, was the idea that he'd killed others far more casually (on purpose) in Batman v Superman.
In the opening sequence, where Superman rescues Lois Lane, it had been assumed for a while that Supes killed the terrorist who terrorises Lois, but not according to Zack Snyder.
Word of God now says that the terrorist actually survived, taking Superman's kill count back down. He probably wasn't in good shape, given that he was smushed through a wall, but he's still around.
In a text message shared online by Reddit user SpGrnv, Snyder confirmed the damage was severe, but not fatal and that the victim is “not dead but not a problem either.” So, Superman isn't a dark killer and he definitely didn't kill needlessly.
Batman still did though. Lots of people, in fact.