[It's not so much that he doesn't think Fern should feel bad as he's kind of scared of what he now knows he's capable of. Fern doesn't look like he's about to jump from his bed into Min's and attack him, but how is he supposed to know he won't if he reacts in a way that makes him see red?]

I didn't say I didn't want you around. But you... you killed someone. On purpose? Of course I'm going to be afraid of you.

[He probably shouldn't have said that last part, but it slips out before he can think better of it.]