I'm all for going with your gut instincts.
When I first started out with my t and she became aware of my triggers she apologized on those occasions when she inadvertantly triggered me. There were times when she'd trigger me and I'd yell, "STOP!!!!!" and she'd say, in her very caring and compassionate and warm way, "I think you're not yet ready to hear this." A few years into treatment, when I still reacted to certain words (such as 'abuse') she would say, again in her warm gentle way, "I think you need to hear this. Can you tolerate it just this time? Take a deep breath and relax.... " And she'd listen to me talk about what the word triggered.
It's now years later and I don't get so easily triggered by stuff she says. I'm stronger now, so I could contain it better.

I wanna share an incident. I took my 9-yr old daughter to a therapist. (School said she's acting out and referred my daughter to an 'excellent therapist').
My daughter has never met this woman and she held onto me, clinging, at least for the first 20-30 minutes of the session. She was too scared to stay with the therapist in the room and needed me in there. I'm ok with that, I understand it takes her time to develop trust in this therapist. I figured I'll stay in the room with her for the first session or two and gently wean her off it.
So therapist sees my daughter clinging to me and she says, "You're not a baby, you don't need to hold onto mommy like that!" A few short minutes later, "You're a big girl, you can let go of mommy, you're not a baby!"
I called her the next day and asked her if it's ok that I ask her about things I notice in session. She said by all means I should ask, so I went ahead and asked, "I noticed you were telling my daughter she is not a baby. You mentioned it more than once, and I'm wondering how that is helpful to her." Honestly, I expected an apology from her. I expected her to say she erred and would be more careful in the future. But to my utter astonishment she said, "She WAS acting immature, wasn't she?" I said, "I think she was acting her age as an anxious child" Her response to that was, "She was not acting her age and I talk to children according to the way I want them to act." Huh? By telling my daughter she's not a baby my daughter will stop 'being a baby'?????? Never mind that she wasn't acting like a baby to begin with, she was acting appropriately as a 9-yr-old anxious kid!
Anyway, I told her I would no longer bring my daughter to her. I wasn't gonna let her psychologically hurt my daughter again. A good therapist would recognize that my daughter's clinginess was due to anxiety and would probably reassure my daughter that it's ok to be anxious the first time.
We really have to trust our gut instincts when it comes to deciding whether a therapist is helpful or not.