I think you put it very well, that you triggered your ex t's insecurities and then she re-traumatized you in her (uncontrolled) triggered state. It is very scary, happened to me, too. But, for me, the retraumatization wasn't entirely, or sometimes much at all, conscious because of defenses (dissociation, etc.) still in place from the original trauma.

There's a blog on the main PC site that wasn't meant to address therapy but I think it applied in my case. I mentioned it on another thread, but am posting it here because i know you're training to become a T. If it's something that T's can be taught about in advance and warned to look out for it in their clients, then maybe therapists can help recognize this pattern and do something else about it before we have to reenact and learn the hard way -- if we ever do. T's aren't perfect, of course, but we do legitimately look to them, I think, to know more about this kind of stuff than we do.

https://blogs.psychcentral.com/knott...-relationship/