how informed does Informed consent need to be?

At what point is consent informed enough and when are actions deplorable but not criminal. I've seen a trend of criminalizing unethical behavior that strictly speaking isn't actually criminal. We seem to be losing the ability to separate and accept that there is a great area of something being an asshole move without it being a crime. 

I started thinking about this again die to reading an article about a woman who posed as a man to have sex with her friend. http://www.lgbtqnation.com/2015/11/woman-who-posed-as-man-to-have-sex-with-friend-sentenced-to-eight-years-in-prison/2/    

She was convicted of sexual assault.  In reading the article I saw that the friend consented to wearing a blindfold and having sex with a guy who was a virtual stranger. So consent was there, informed consent well that is rather subjective. How informed did she need to be and who makes that determination? When is a person not informed enough for the lack of information to be a crime?  Would the complainant have felt the need to pursue charges if upon the unmasking her mystery lover was a guy but maybe of a ethnic background other than the one she'd assumed him to be (or even told her he was). What about if he were really physically unattractive or possibly if he were still a woman posing as a man but someone she didn't know?  

Due to her decision to go along with lacking knowledge of the person she was spending time with it feels dishonest to me to then turn around and refuse any responsibility for her own lack of due diligence. 

The woman lied about who she was but was the lie somehow more of a lie than if she had been an impotent man using a prosthetic penis, or married or whatever?  Make no mistake, I think it was all kinds of shitty behavior on her part I'm just not ready to call it a crime. Misrepresentation can be criminal but the lines blur when there is consent to remain in ignorance.  By not insisting on face to face interactions there is implied consent of not really knowing who she was with. Which there is nothing wrong with. We all do risk assessment and decide for ourselves what is worth it but we cannot claim to be grown enough to make our own decisions about our acceptable risks then decide that heads must roll when those choices don't play out in a manner we find acceptable. When did we lose the ability to chalk stuff up to bad experience/learning experience/some people are assholes and move forward with our lives secure in the knowledge that whatever else we lived as we thought best.