[adventured]

I would call it saving it.

He specifically acted against bad information and what he was supposed to do, which required bravery and critical thinking to avoid catastrophe. It was also potentially risking very bad consequences for himself, as his superiors easily could have put him in prison, disappeared him, or otherwise punished his life - even just out of spite - for what he did. He says it was a good thing that he was working that shift and he is right. The odds are extremely high that anybody else would make that phone call up the chain of command, and from there the odds of a nuclear response escalate rapidly.