I see evidence of a sexual violence; and I see evidence of multiple perpetrators; I also see evidence of Amanda Knox's involvement, and of Sollecito's.
I also see evidence that the crime was committed by someone under drug effect and that all three were on drugs that night.
I also see evidence that all three had contacts with drug dealers and had - each one in a different way - some issue regarding their sexual conduct. And also they had some relation with violence or violent fantasies and knifes.
This question makes sense.
In fact, out of my legal knowledge, I did expect the Supreme Court to crush the verdicts completely, but out of my logical sense, I did not expect them to accept the calunnia conviction (while only nullifying the lack of aggravating circumstance).
But, I acknowledge that the decision is sound and logical under a legal point of view. The technical reason in fact is that it does not rest strictly on Hellmann 'competence' (side observation: thecnically, in the legal lexicon, Hellmann's court was 'competent', because 'competent' in legalese means 'it has jurisdiction' on it). In fact, paradoxically, the calunnia conviction could be reviewed if it was proven that Hellmann was corrupt; in that case, the Supreme Court could declare their guilty verdict subject to review (they can't declare it null, but they could appoint another panel that would review the decision and may theoretically overturn it; as it happens in the US for case reviews too). But if Hellmann's decision was just wrongly motivated, well, here we come to the point of why the actual decision of the Supreme Court was sound and logical. Because the Supreme Court decides upon a recours, which consists in reasons and arguments, presented in written and oral form.
It does not rule on Hellmann's verdict. In fact, even Hellmann is itself an appeal court and Massei is the first instance convicting court; the calunnia is discussed by Hellmann court only on the defence's request, and it is discussed by the Supreme Court only on the defence recourse.
Thus, the Supreme Court does not rule directly on whether Hellmann court is good or bad, but on whether a party's reasons for compleint are good or bad.
The calunnia conviction stands not because Hellmann's court was "competent", but because the reasons provided by Ghirga-Dalla Vedova against the calunnia conviction were inconsistent. Devoid of merit, unfounded, inadmissible or wrong, anyway ineffective.
And indeed their reasons were flimsy and doomed, as I explained in my report about the High Court hearing.
Paradoxically, if Ghirga-Dalla Vedova argued on grounds of bias or suspicion of corruption of Hellmann, they might have won. I can't say that for sure but who knows.