When it all first happened, that was my thought too. I thought she either was very intoxicated and/or possibly had drugs slipped into her drink.
I also think that she was taken advantage of by at least one of the "boys" if not all three. When you are under the influence, I don't think that you can legally consent to anything.
Then, something unintended went very wrong.
I think that if the truth was told or uncovered at the beginning that charges (maybe manslaughter - not murder ) may have been made. Now, with all that was covered up and bungled, I really don't think any charges will be made. I also think she is no longer on land. Of course, just my $.02.
I think that Vandersloot's father knows what happened.