None of that is casual.
Besides, defense of others is always a legal defense, even if it was in the US.
Here? Kahndaq would give him a medal, once they get rid of their current official government.
And it's not like OL hasn't made it clear to the Justice League before that he's perfectly willing to heap the bodies high if the need was dire enough; see what he did during the Alien Invasion Training mission.
Or what his Go To Hell plan was.
He's spent most of a year learning English from tutors.
You expect him to sound somewhat modern.
Besides, compare the speech patterns with those he used in Fawcett City; they seem similar.