I agree with Parva that not every "safe" situation we perceive is not actually safe, rather than a predictable situation in which we know very well how to behave. Unpredictable situations will cause arousal and drive us from our comfort zone.

Sympathizing with the abuser, I guess and from what I read previously, means that the abused has identified so much with the abuser. It makes us in a way give "excuse" to the abuser for his actions because we identified with him so much. This will turns the self against the self because we will perceive ourselves as the only culprits in what had happened to us. The shame will be directed towards ourselves and we will suffer immensely.

Other reasons I guess, is the concept of reenactments. we reenact past situations as a way to master them, or because we developed rudimentary defense strategies that no longer work in our adult life.

I attached a paper that talks at lengths about the reenactments. Hope it can help everyone.