Rosie knows the differences, too, which is probably why she feels as bad as she does. One of her own worst experiences in life was because of her wounds being poisoned, forced to become infected and fester- She has the scars on her back to prove it still.

It's reasonable that he's scared, too, and says what he does due to it. That doesn't make it hurt any less though. To have her apology discredited, her motives questioned- To feel like the very monster she doesn't want to be and never did. "Very, if you think I wanted to hurt you," she manages to snap, but her own breath catches in a hiccup due to her erratic breathing.

"I didn't! I don't. That's the last thing I ever wanted to do again, just-" A strained sound of frustration sounds as she shakes her head. "All I'm trying to do is make it better."