Why was Kiowa so insistent that the man Tim killed deserved it?

Kiowa is a good friend to O’Brien, sees that his friend is shocked and tells Azar to leave them alone. Kiowa reasons to O’Brien it was a “good kill.” It was at least a reasonable kill; the man turned out to be carrying ammunition.

The story ends with a one-sided conversation: Kiowa trying to get O'Brien to talk and O’Brien remaining silent. This conversation illustrates the limits of friendship. No measure of companionship can make up for the stark reality of life and death, and the moral consequence of what O’Brien has done. O’Brien feels guilty, and his friends cannot console him.