I think this is an important topic. Thanks for bringing it up. Disclosure: I am a grad of the 2nd Corps who knew Wierwille personally. I was a limb leader's wife for a time. I was on the research team, too.
From my experience in the cult, and from knowing a variety of people in it over the years, I'd say victim/perpetrator is pretty black and white, but probably those are useful words to apply as we attempt to clarify who bears responsibility for the darkness perpetrated by the system known as TWI.
But as Oakspear says, applying the correct label correctly, if we chose to do it, is complicated. People varied in level of responsibility and attitudes and intentions.
That said, I feel some measure of guilt about having been someone who sang TWI's praises, keeping myself bundled up in a cloud of denial, thinking I was promoting the greatest ministry on earth. To make amends, I do what I can .... moral outrage is appropriate, not only for outsiders looking in, but as a response from those of us who left.