Right you are.
So... Mab. I feel like my basic "Why Mab" argument isn't affected by Lea being available (or not) as Mab's agent.
You do realize that my post doesn't disagree with you about the first attack?
Another possibility; but one which too little is known to put together a detailed description of, is there is more than one party at work in Proven Guilty, maybe several.
Two as I see it. Mab and the Adversary represented by his allies.
And we know a lot, but only in hindsight.
Who is manipulating Lily? Maeve. And we know now that this was the first step in her Mab is crazy campaign.
Who is manipulating Maeve? The Adversary.
What group is at least a fellow traveler with the Adversary? The Black Council. Whose existence is deduced in the recap.
That something exists that can possess the second most powerful person in faerie.
That Rashid has it within his power to use the gate to watch events unfold in the world including acts of Black Magic.
That Mab has been watching both Harry and Molly. Perhaps since Death Masks.
Maybe why Arctis Tor was attacked.