As far as Scorpions go honestly this was our win because we were able to hurt her, so now everyone knows the Nothing is involved.
This here is also correct.
Unless she happens to be just a murderous Utaku (Which is unusual given how high their Honor is, they would absolutely take care not to kill a man in a duel to first blood), this was totally an agent of the Laughing Darkness--and we wounded her in full view of the audience.
The secret is out, and an official investigation is now underway that they can't fully hide from.
And best of all? Technically, we defended our own position and the position of the Scorpion delegation too
Kharmic Strike means that both sides are right--except in this case, the other one was unmasked as a monster. Thus, not a Samurai, and thus, not eligible to be correct in an Iaijutsu match.
Technically speaking, Naoto dying here was a perfect move for the Scorpion delegation. He wasn't a courtier, and he was incredibly inexperienced. He took a dive and in doing so, proved that there was dark deeds afoot, while basically making the Mantis our bitch in reparations for using a "Tainted" Samurai as his Champion, and locking the Matsu into basically repaying us for bringing the rot to full view.
From the clan's point of view, this was a massive coup, unless it just turns out that "No, the Utaku was literally just a murderous bitch who would randomly set aside her honor just because lolscoripon". We've got the sympathies of virtually everyone involved, and revealed a genuine threat on the way down.