Ok, since you put it that way, let's move on to Triss' shoes. Her current situation prior to rescue: locked up by the Nilfgaardians. We're not sure how the Nilfs interrogated her (from the accounts of others, the Nilfs seemed to have a way with extracting information), all we see (if we choose to save her) is that she has bruises, blood marks, and signs of being whipped.
I'm not convinced that Triss would be as understanding as you put it. Here's why:
a) I don't know what happened in the Battle of Sodden Hill, but apparently she has been severely injured and even disfigured by the Nilfs, and she sounded traumatized when she recounted it in the book, Blood of Elves. So to have fallen into the hands of Nilfs again, rendered helpless, and possibly to never see daylight again, I can't imagine the horror that she might have felt.
b) Triss has always been somewhat insecure about Geralt's feelings toward her. For one, she felt like she betrayed Yennefer. If she learnt that Geralt chose a child stranger (one that is weaker than her although both are equally helpless in their confines if you think about it) instead of herself, I'm not sure if she would be that open-minded about it.
c) If Triss found out what Radovid did to Phillipa, I'm not sure if she would be that "understanding" that he didn't come earlier.
d) Let's say Geralt decides to save Anais. Triss could have been killed/raped by the crazed mob, or more likely brought back to Nilfgaard (!!!). Up until that point, no one (not even Triss) would even come close to expect that Letho would save her. I'm not sure Triss would be so understanding when she could have been in deep shit were it not for Letho.
I think a lot of us are taking for granted that Triss gets saved no matter what Geralt chooses - it's ok, she comes out of the whole mess alive anyway, right?
"In this situation, Geralt can't make a choice that is wrong in anybody except Triss's eyes". If say Zoltan or Dandy knew that Geralt went to rescue Anais and left Triss to her own fate, I'm sure they would be very unhappy / repulsed by the idea.