How did the Justice System fail? Did you see the facts from the Search Warrant? That is definitely not the kind of (alleged) victim that you want to put on the stand. Whether or not she was raped, I have no idea, but her "fuzziness" of the situation and the fact that the blood work done shows no reason why she doesn't remember anything (i.e. - BAC was .04 & there were no date-rape drugs in her system), I think the justice system actually worked. No signs of trauma and another man's DNA are just added facts that bolster the decision to not file charges.
As expressed in the SI article I posted, the justice system failed because charges are normally either filed or not filed within a week of when these types of incidents occur. Trials are prosecuted in the time that it took them to decide whether to bring charges (a ****ing year). Also, there were people who should have known about the allegations (like the sheriff) who weren't made aware of them.