[He's just listening to this trying to keep a neutral face over the revelation that not only did he kill his mom, he did it by burning his house down. He scratches a little at his arm, sighs.]

. . . I know from experience that it may be impossible to believe this, but I'll say it anyway. You are not responsible for what some powerful person did to hurt you. You were a child.

[He does know that might be taken badly, because he would take it badly, if someone said that about him. But it still seems important to say.]

I like your idea to make up for it, though.