Dorian: So I hit a nerve with the whole "murderer Grey Warden" business.
Blackwall: Are you speaking to me?
Dorian: Yes, you. Blackwall, or whatever your name is.
Blackwall: "Blackwall" will do.
Dorian: I'm saying I understand wanting to atone for one's actions.
Blackwall: Is that so?
Dorian: Enough to know when I've stepped in it. So I apologize.
Then, a few minutes later:
Blackwall: You... did not have to apologize to me, Dorian.
Dorian: People who say that to me are usually wrong.
Blackwall: I am indeed a murderer, and I escaped my past to become a Warden, like many others before me.
Dorian: Obviously the original Blackwall saw something in you. I respect that.
Blackwall: And you abandoned your life of privilege for the sake of principle alone.
Dorian: I didn't like that life.
Blackwall: It was wrong of me to lump you in with peers you hardly resemble.
Then Dorian said "truce" and Blackwall replied "gladly", although I didn't get the exact text on that. part.