Fiorina was never implicated. Fiorina was fired two weeks after the document was leaked, so even if she technically started the investigation (though you'll also find sources to the contrary such as
this one saying Dunn began the investigation) she almost certainly had no time to have done anything illegal.
Ultimately, neither CEO was held responsible for anything of the illegal activities that happened. Fiorina was never accused (by law enforcement) of anything illegal.
There are plenty of valid reasons to question Fiorina's competence as an economic advisor to John McCain, why stretch to accuse her of things that carry little weight and probably only a slim relation to reality?