>>212702188Context matters. One is an extremely contrived situation forced so Superman would directly kill his foe, because that's the sort of thing the director wanted in the film, even arguing for it over the producers of the film, who wanted Superman to throw Zod into the Phantom Zone at the end instead. That we just watched him punch Zod around the city and through buildings for ten minutes beforehand also makes him suddenly being able to kill him with a neck snap rather goofy and again, contrived.
The other is Hawkgirl, a generally more ruthless hero than Superman, deliberately killing a villain, immediately after stating Superman would never do what she's doing, and tying into the themes raised early in the film where Superman took definitive charge of a complicated political situation without considering the widespread consequences, Hawkgirl is doing the same, albeit more permanently, and no doubt there will be ramifications in the world. However, as Superman also said, people were going to die, so it raises a Gordian Knot kind of solution. Which is ironically the kind of rumination on the role of super powered people in a more "real" situation that the Man of Steel film sort of played acted it was exploring but didn't really say anything.