IMO, there is a combination of misquotes or poor choice of wording on behalf of the media, combined with hearsay/rumor. Added into that mixture are different accounts of what happened by family members, some of which are being stated second hand.
It's hard enough to try and deal with the speculation that gets stated by just what is printed in the media when they are rushing for a story. What we have here is a big barrel of monkeys of info to speculate on, when you combine all the different elements.
IMO, if there was a party there are definitely people that spoke to LE. Willow has been found and they made a quick arrest. They might not know 100% of the story unless there were witnesses but they do know a lot of the details such as how and what was used to transport her body along with when the actual death occurred. They know the answers to most if not all of the questions that we all have.
Some LE agencies will share a lot of the details and some will say nothing. I hope they give enough information to clear up a lot of the wild speculation, at least for the sake of the family and the community.