When you didn't respond to the mention of OM, she even tried to get a reaction out of you later by texting. I think that every time you remain calm in your responses, you build her trust in your ability to change long-term.
But he didn't do this, He had a reaction and he did respond...and his W knew this. She's not stupid.
Patience is bitter, but its fruit is sweet. --Jean Jacques Rousseau.