They weren't out of options -- they hadn't even subpoenaed her!  She went from being a witness voluntarily cooperating with the police and courts to being illegally jailed in no time flat.  

I read the ruling of the trial judge, who specifically found her testimony credible and coherent, and that her incarceration was unjust and apparently based on misunderstandings of fact.
https://www.canlii.org/en/ab/abqb/doc/2016/2016abqb706/2016abqb706.html?resultIndex=2

If you want to cite evidence from the transcripts to substantiate your view that she was "barely reliable" then feel free, and post a link too.  Really, I don't get it, and neither did the trial judge who did read the transcripts.  

And you seem to have avoided the question about why you think her having done drugs for a brief time in the past is relevant to anything.  To my ear, it sounds like an excuse to justify jailing her after the fact, certainly not a legal reason to have done so.