The masters were not backstabbed, they were confronted, lectured, and even with their defenses up, aware of Traya's presence, she broke right through them.
What did she actually do,
From what I understand from the dialogue in the game, she 'shows them the galaxy through the eyes of the Exile' - and when you inspect their corpses in the game, it's as if they no longer exist in the Force.
From that, I always took it that she exposed them to the same level of pain and horror that caused the Exile to voluntarily sever herself from the Force to avoid the backlash - hit them with a wound in the Force. In essence, she hit them with Malachor V, right in the face. And because they couldn't sever themselves from the Force, because they were too dependent on it, they died.
But... would that work against Revan? Traya has such a love for him because he's the greatest student she's ever trained - better than Nihlus or Sion, because unlike them, Revan isn't dependent on the Force, presumably. That's the quality she seems to most respect and prize. And he's familiar with Malachor, so...
And, can she do it when the Exile isn't there? I assumed that because the Exile was there, and the Exile carries the horror of Malachor around with her, and because the Exile and Traya were linked, that Traya could do what she did then.