In an interview with the Empire magazine podcast, Man of Steel screenwriter David S. Goyer revealed that producer Christopher Nolan was opposed to the controversial ending to Man of Steel.

The godfather of gritty, realistic superhero films was apparently not willing to go quite as far with perceived changes to Superman's character as was the Watchmen director.

"Killing Zod was a big thing and Chris Nolan, originally, said there's no way you can do this," Goyer told the magazine. "That was a change--originally Zod got sucked into the Phantom Zone along with the others and I just felt it was unsatisfying and so did Zack. We started questioning--we talked to some of the people at DC Comics and said, 'Do you think there is ever a way that Superman would kill someone?' And at first they said 'No way, no way,' and we said, 'but what if he didn't have a choice?' Originally Chris didn't even want to let us try to write it and Zack and I said, 'We think we can figure out a way that you'll buy it.'"

He acknowledged that it's a shocking and possibly uncomfortable scene, but that they've hopefully set up the mainstream audience to question what they know about Superman.

Director Zack Snyder also explained the decision that went into killing, and how it will affect sequels to come.

"I guess for me--and in the original version of the script he just got zapped into the Phantom Zone--David and I had long talks about it and Chris and I talked long about it and it was like, 'I really think we should kill Zod and I really think Superman should kill him,'" Snyder explained. "And the why of it was, for me, that if it's truly an origin story, his aversion to killing is unexplained. It's just in his DNA. I felt like we needed him to do something, just like him putting on the glasses or going to the Daily Planet or any of the other things that you're sort of seeing for the first time that you realize will then become his thing. I felt like, if we can find a way of making it impossible for him--like Kobayashi Maru, totally no way out--I felt like that could also make you go, 'Okay, this is the why of him not killing ever again, right?' He's basically obliterated his entire people and his culture and he is responsible for it and he's just like, 'How could I kill ever again?'"

He said that after Zod's purpose was taken from him, he was nothing but a killing machine, and there was really no putting him in jail and walking away. He compared Zod's actions to "suicide by cop," tying it back to the repeated use of "a good death is its own reward" in the movie. The warrior bred, Snyder said, felt that if Kal-El was capable of killing him, then that was an honorable way to go after having failed his people.

He also said that in potential sequels, Superman having killed Zod will keep the audience from becoming complacent and thinking they know Superman's limitations.

"I think that when you really put in stone the notion that he won't kill, it erases an option in the viewer's mind," Snyder said. "That doesn't mean that he doesn't now have a code that 'I just won't do that; I have to find another way.'"