[There's the barest hint of a frown at that comment because Poe doesn't have to say who he's talking about for Leia to know what he's hinting at. She'd seen Ben in his helmet, and it wasn't a memory she liked to remember. It was, after all, when Ben had shared what he did to Han.]

That's where we'll have to differ, then. I've made my opinion on him known, and nothing I've seen has proven otherwise to me.

[Because she doesn't think there is light to him. Even here, even now. None of that light made itself known to Leia, so she has no reason to trust its existence.]