I don't remember that either. lol
But probably the decision is let Tristian lie, cause the Philip of my save is romantic type. He didn't tease Juwete, didn't let witch take advantage of him... So I think he didn't want to disappoint Isabella and honestly the brothel scene is not his fault in my opinion(Maybe, I only remember his father took him there).
Then again... RPGM's save system is really horrible! For that situation, you need to save anything in the same slot #42, then replace it with my save, which will work properly. So actually you didn't need to overwrite your old save.
My bad, I should explain it earlier. Sorry.