She's a lot less gentle in the next issue - interestingly, after she gained the ability to talk and lost the ability to read body language. There's a man who shoots another guy who was on his side and, well... She beats him viciously and then stops his heart for three beats to give him a taste of what it feels like. Batman is watching the whole scene, but he's too dumbstruck to react. Then he tells her to protect the man they've just rescued from other attacks and tells her to refrain from teaching anyone anymore "lessons" that night.
I've always wondered what we were supposed to get from that exchange. That she's ultra loyal and can't imagine taking down someone on your side? That she can get angry and not lose control? That - like Batman learns - she may have lost her special skill, she's no less in control of her own body? All of the above? There was a lot in that scene.
Bruce has the excuse of the shock of seeing the video. 'Sides, it occasionally comes up that he's not always as mindful of his own safety as he should be, especially in times of emotional duress (lol understatement). And it drives the point home that Bruce needs people around him to help him, otherwise he'd get very dead.