For ex, the Council does recognize self-defense exceptions to the First Law. Did she kill her rapists in the process of defending herself...or in revenge for the assault? Did she use magic to try to defend herself...or did she go past self-defense into something else?
They do, but without a good advocate what chance does the accused really have? When Harry was dragged before the Council to be judged, he was a scared kid with a hood over his head, they spoke in Latin, he didn't understand a word of it. What chance did he really to defend himself if Eb hadn't come forth? Given the recent history of the Council and the attitude of the Merlin, Hannah would have had no chance... And there is also this, how much knowledge of the Council and her rights did she have? If she only had rumor to go by, of course she ran... Harry was totally ignorant of both the Laws and the Council.. In my opinion if he had a clue at all he too would have ran.
Of course there's always the issue of whether she was believed or not, Harry was acting in self-defense but the truth of his claims were doubted. But then again, Harry himself notes that Eb was not the only member of the Council who had sided with him, either. How much of Harry's problem was Morgan's obsessions?
His problems with Morgan came later because he was of the same mind as the Merlin that potential warlocks once they've crossed the line cannot be reformed. It is unclear how much they sided with Harry, they were mostly afraid of this kid with so much raw power that he could take out a former Warden in a duel.
Hannah's case is not necessarily a binary "Telling the truth or lying" thing. She could be telling the truth and the matter still not be entirely as she describes it. The more so with Lasciel whispering in her head...
Oh I think it can be the truth and exactly as she described it down to her bitterness after her friends died.. The question is more about what happened after that. Here is my theory, Andriel sees and hears everything, so through him, Nic would be aware of Hannah and her plight. Nic also knows that Lasciel was rejected by Harry and is none too happy about it. So from there I don't think it would be too hard for him to arrange "contact" between Lasciel's coin and Hannah.. We know how good she is at twisting the mind, we saw what she was able to do as "Sheila" to Harry in Dead Beat, only he was saved by Butters pointing out there was no Sheila. He was saved by that and the fact he had had an earlier soul gaze with a Denarian in Death Masks and didn't want any part of that club. So it isn't too hard to believe Lasciel could manipulate someone already angry and very bitter with promises of revenge for her friends.