Well people do make mistakes and this was a doosey. The mistake could be accounted toward a faulty test, stress of the officers, etc., but ultimately I think that they need to be a hell of a lot more careful in situations like this.
I know that extra testing takes time, but she should not have been in jail for two weeks before more testing was done. That is a little excessive. I think she has a case, and as much as I respect the criminal justice system as a whole, when it screws up this royally, it should be held accountable.