RAI, for what it's worth, my STBX has said that he's sorry I'm hurt, but has never acknowledged that he chose to do the hurting. To me, it's like saying that you are sorry my leg is broken without acknowledging you were the one who ran me down with an 18-wheeler. But I have chosen to believe that's the best apology he can offer right now, and I think that deserves an olive branch for the sake of my children.
You are correct that saying nothing at all is better than a scathing reply. Better for her, and far better for your kids, but not necessarily for you. Because all that anger and bitterness and resentment is still inside you, and that's what we are trying to get you to let go of.