The intended meta-content was that she understood her kind-of grudge against dath ilan was not something Keltham would necessarily be sympathetic to, and she wasn't sure future-Carissa would share it - thus specifying that it was something she felt right now, not necessarily a long-lasting state of affairs. She tried piling on a lot of disclaimers- "kind of", "a grudge", "right now", to make it clear that it wasn't an endorsed anti-dath-ilan position she was advancing, or a policy she was demanding in full generality but a current and specific need.
Also, that wasn't the only time.
There was an earlier time, where she told him that the conversation would be less painful and more bearable for her if he'd stop bringing up dath ilan, which he did not see fit to acknowledge as a request at all, and a later time, when she was just on the brink of giving up, where she told him that she didn't know if the approaches that seemed to her like they ought to work really would, since they hadn't been tried, and so was willing and ready to proceed only by dath ilani rules.
He could have told her then that he was open to negotiation, if he was, which he gave no sign of.
Carissa thinks that sensible ideal agents might, in fact, try two times to quietly bring up something important to them, and get refused both times, and then try saying more explicitly that they have ideas for how things could work better but those ideas haven't been tested and they're willing to just obey the other's protocols.
She thinks that, actually, nothing Keltham did had anything to do with his inability to understand anyone who doesn't behave like a sensible ideal agent. He was not behaving like a sensible ideal agent.
He was behaving like a scared, injured traumatized person who didn't want to give Carissa the thing she said was important to him and who wasn't actually very interested in her ideas for how communication might work, especially since she disclaimed that she didn't know if they'd really work. She was behaving like a scared, injured, traumatized person who wanted Keltham to stop doing a thing that was really hurting her, was aware she had no leverage for this request, did not know the magical words that would render her permitted in his framework to make it, tried a couple of different ways of making it anyway, and then gave up and told him she was giving up and adopting his framework.
She is actually fine with the fact she gave up and adopted his framework. There are important battles to pick here and this isn't one of them. But she is sad, if Keltham's narrative about his prisoner trying to tell him what she needed, being refused, and then figuring out how not to need it, and then telling him she had done that and communicating by his rules from then onwards, is that she could simply have said the magic words if she wanted something different to happen. She did not know the magic words.
She tried to talk to him with the only words she had, and it didn't work, and so she gave up and did the rest the dath ilani way for the rest of their acquaintance without ever complaining about how much it hurt her, and she is fine with the fact that this happened, but she does think that it did happen.