As for Chanel's guilt, I think your downgrade K7->K5 happened because you made certain choices that led to it. My point is that KG is a pretty complex game in terms of a lot of decisions (not always obvious) and a lot of the same variables that can affect your main MC. Judging by your MC's stats, you chose the Dom path, but somewhere along the way you slowed down, allowing Kane to act as a sub and this is the result. If this doesn't conflict with your playthrough style, I would strongly suggest using the Sancho Mod (MultiMod) or at least the official walkthrough.
I can only confirm what the players above replied to you - in the actual Good Dom walkthrough, Olivia will never throw darts at anyone. So there's nothing wrong with the developers' logic. Good Olivia does a minimum of bad things, and what she does do is more geared towards looking good to the sadistic women around her.. Like letting a common slave lick her pussy or letting a slave kiss her heel in public. (etc.)
Olivia, like Kane, makes a number of key decisions that affect the development of her personality and even the characters around her (not all of them). Therefore, it is up to you to decide who your Olivia turns into. For example, if you let her play "fake cops" - there will be one outcome (triggering one of the important decisions), if you choose a different path, it will be different. Anyway, try, experiment, or use a mod/walkthrough if such experiments are not to your liking.