Quote 1
"I'll tell you the straight truth," he said. "The guy was dead the second he stepped on the trail. Understand me? We all had him zeroed." (The Man I Killed.31)
Out of friendship, Kiowa is shifting some of O'Brien's guilt about killing a man onto himself (and the rest of the platoon). This calls back to the first quote we discussed here; the soldiers "shared the weight of memory."
Quote 2
"You did a good thing today," [Kiowa] said. "That shaking hands crap, it isn't decent. The guys'll hassle you for a while—especially Jensen—but just keep saying no. Should've done it myself. Takes guts, I know that." (The Lives of the Dead.20)
The casual nature with which the men treat the dead stems from wanting to protect their reputations and show toughness, but they know it's not right. Kiowa recognizes that it takes guts to show that you're not tough.