@Mira
The point of bringing up the attack at Raith Manor is to point out that once Harry had led the skinwalker to the Alphas, that someone would die if the skinwalker wanted them dead. The Alphas had not a chance in hell. This is the nature of Harry's failure. Harry as written, believed in two contradictory things, that he could protect them by keeping them in the dark and that he could use them without this eventually happening.
No, the event with Kirby happened before that attack on Raith Manor... Biggest point Harry had no clue what is was he saw, it put him in a state of collapse when he showed up at Will and Georgia's house... Only after the first battle did he realize it was a skinwalker, and he told Will straight off....
1. Kirby died because Harry withheld information.
No, Harry had with held nothing, all he knew was it was big, bad, and so ugly it made him catatonic, he conveyed that information, the pack still backed him..
2. The skinwalker was going to kill Kirby no matter what Harry did
Most likely, only difference Kirby would have known what killed him when it did..
I don't understand how anyone can agree with both statements. (I agree with statement two, mostly. The skinwalker killed Kirby as a message; therefore, it could have killed a different Alpha because Harry did something that lead to different results, but the skinwalker was definitely going to kill an Alpha if Harry went to Will's place).
I read the quote, mostly because I can't see how fully briefing Billy would have changed anything, as either Harry illogically blaming his withholding of information for Kirby's death or simply stating that Billy wasn't going to follow blindly because Kirby died. Kirby's death cements the seriousness of Will's role as leader for Will.
No one has demonstrated how Harry briefing Billy on the wider world of the supernatural could have saved Kirby. Until someone does that, I'm going to remain obstinate in my position that Harry's withholding of information did not get Kirby killed. I'll go so far as to say it is hypothetically possible, but that's it until someone can at least give me a hypothetical.
Even if in the text Billy said "Kirby is dead because you withheld information from us," and Dresden said "That is correct," I would still say "what" because, as you said, the skinwalker was going to kill whoever it wanted anyway.
How about instead, we take everyone's position, average them, and agree that I'm right? 
Page 29, Harry is just coming out of his catatonic state at Will's house...
"What is it?" Billy asked quietly.
"I don't know," I said. "But it is real bad." I glanced at Georgia.
"How long was I down?"
She checked her watch./ "Eighty-two minutes."
page 33
Just after Kirby died..Billy looked up at me, Kirby's blood all over his face and hand.
"What is it, Harry?"
"A Native American nightmare," I said, I looked at him grimly, "A skinwalker."
Then on page 35
"What are you going to do?"
"Find out why it's here," I said. "There's Council business afoot. Christ, I didn't mean to bring you into this." I stared toward the knot of officers around Kirby's corpse. "I didn't mean for this to happen."
"Kirby was an adult, Desden,"Billy said. "He knew what could happen. He chose to be here."
Which was the truth. But it didn't help. Kirby was still dead.I hadn't known what a skinwalker was before, beyond something awlful, but that didn't change things..
The attack on Raith Manner didn't happen until page 180... So how could have Harry used that information to warn the Alphas about the skinwalker that he had run into back on page 20 something that he only knew was bad, ugly, and dangerous, no name? When as we saw back on page 33 he just found out was a skinwalker and Kirby was already dead! Since Harry had no clue what the big bad ugly thing was how did was he deceptively leading the Alphas to it?
page 219.... Will tells Harry he had talked to Kirby's folks....
I sighed. "I'm sorry."
He shrugged. "Kirby knew the risks. He'd rather have died than stand by and do nothing..
It is a little further down when Harry says...
I nodded. "It's part of something bigger I cannot talk about everything that is going on.
That is when Will becomes unglued, he does say perhaps if they knew more, maybe Kirby would still be alive... However he knows perfectly well as we the readers know Harry didn't know what it was they were going up against when Kirby died back on page 33... And even if he knew, Kirby and company would still have been there for Harry..