First of all, we've never seen a scene like that before or since, and we certainly have no shortage of scenes where people died while an Echo-haver was around to facilitate it. I genuinely think that's just how Fordola perceives what she did, rather than in any way what happened.
And as for why it contradicts... well, because it's Fordola. Fordola's far from stupid, but she's also not exactly the smartest person, nor the person most capable of readily taking new facts on board. Even if she was told that was how it worked as far as things looked (and honestly I don't think anyone would've told her), does she really seem like the type to believe that when she already has a strongly-held belief of what she has to do and why?