It's still the same very basic mindset. As we've seen, both Superman and Batman when they started out had abslutely no compunction about killing people who needed killing. They were following that most American of directives, written into the constitution that when something goes wrong that the people who are capable fo acting to end it have the obligation to do so. And as janegray points out, it's not like the people Danny killed were ever going to stop what they were doing or were even slightly repentent about it.