There are always multiple ways to do anything. There aren't always multiple correct ways to do something. Given that there is no rigorous definition of what a scene is or is not in DFRPG, we have to go by general usage and common sense. And by those standards, it's all part of one long, multi-chapter scene.
Let's talk about that a bit.
Nearly everyone in this thread is saying there's a break in the conflict. You are the only one insisting there isn't. If a whole bunch of people agree on something, and one person disagrees, which group is the one using general usage and common sense?
The summoning of Cowl and the ultra-ghouls doesn't make anyone safe who was in danger before. It puts everyone who was in danger in even more, and pretty much everyone who wasn't at risk before now is.
It doesn't make anyone safer. Nobody's saying it has. What makes them safer is the Einherjar showing up and creating the quiet spot that Harry directly and explicitly references.
And if Harry hadn't been able to counter the gambit, it would have rendered the social consequences of violating the duel's terms null and void. It doesn't matter if Vitto becomes an outcast, or exposes Outsider involvement, if the entire White Court gathered in the caverns is slaughtered. If all the witnesses are dead, it doesn't matter what they saw. Cowl and allies could then dominate the surviving WCVs without having to worry about resistance.
And this largely isn't relevant. Vitto has to escalate his plan and show his cards in a way he hadn't intended. It doesn't matter what would have happened if he'd succeeded because, frankly, most games aren't going to let him succeed. This is Harry Dresden's story, it's the PCs story, and the GM is, generally speaking, going to give them a challenge that they are capable of solving.
It's definitely not a concession. You don't 'concede' a fistfight by pulling a gun and trying to shoot your opponent with it. It's an escalation.
It's a concession because it allows Harry to bring in his back-up. It's a concession because the duel's over, Vittorio lost, and he's losing on his terms.
You are thinking of it only in terms of the physical contest, and that simply isn't the case here.
But the larger point is, at that point,
Vittorio is no longer a participant. By making that move, he removes himself from the ensuing fight scene. If nothing else, the fact that Harry and Ramirez's initial opponents are no longer involved marks an end to the conflict scene.
And then Harry has a distinct, noted, and explicit five minute break.
We don't even need to focus on this particular battle. I picked it because it was a relatively early example of the game rules not matching the novel material. There are plenty of later examples where what Harry can do clearly violates the limits placed on game characters. And you can't even explain the events by attributing things to 'Sponsored Magic' with Winter, because Harry resists almost every case of the mantle's impulses towards violence and destruction. He'd be building up a massive debt that he soon wouldn't be able to pay off.
It's only an example of that after you've dismissed every attempt to explain that he does, in fact, get a break in the action, glossing it over with, "Well,
I don't think he does."
Him resisting doesn't mean the influence isn't there. He is accruing debt, and he's paying it off as it comes.
Just acknowledge the elephant in the room, guys. The game rules don't reflect the canonical increases of a wizard's abilities with skill. Increasing the numerical bonuses on casting, but not increasing the amount of casting that can be done, eventually leads to a break between the setting and the rules.
We've given you several reasons why the rules work, and how they can work in the context of the novels. You've ignored and dismissed them.
Nobody's trying to hide anything here. Please stop acting like you're exposing some awful truth we're not acknowledging.
