Arson seems pretty different from murder and rape and even looting? Or at least, it depends on what you're doing arson to, you shouldn't burn down people's houses and you definitely shouldn't burn down houses with innocent people inside, but it's not like rape where it's always wrong. (Not that she's going to say this, or even let it show on her face when Delegate Oriol i Cornellà brings it up.)
...That's probably not what matters right now. What matters is — they gave a speech about fighting for justice and standing up to Evil nobles, and people heard it and instead of fighting back against people like Delegate Napaciza or Delegate Ibarra they took it as an excuse to murder people like Enric and Valia and Liushna and Blai. And maybe some of them really thought Valia was saying they should do that, if they heard that awful pamphlet, but that's not an excuse, if you think an Iomedaean priestess is telling you to murder innocent people then either Iomedae is Evil or she didn't actually say that and either way you still shouldn't do it.
And instead of hanging the murderers and rapists responsible, they want to prosecute Valia for something she didn't even do.
She wants to see the man who murdered Valia burn to death. She wants to ask the azata how you stop people from taking your words as an excuse to do terrible Evil things, except she heard how much Delegate Ardiaca spent on it and probably he cannot actually spend astonishing sums of money just so she can ask an Outsider 'how do I get people not to do terrible Evil things for no good reason.' She wants someone to bring back Valia and Liushna and then she wants the two of them and Alicia and Raimon to all run off together to somewhere where they can just hunt down people like Raimon's old priest together — only she doesn't, actually, because no matter how frustrating it is to have to argue with nobles and diabolist lawyers and Hellspawn all day, she's doing something important. And also because that's a stupid and pathetic thing to want.
"I don't really care if someone who murdered innocent people was a nobleman or a normal person, either way they should face justice. ...I didn't — realize what had happened last night. I've never even been to a city before. I'm — I didn't mean for you to be thrown off a bridge, and I don't think Valia did either, and I hope the people who did it face justice too."
(At least, she thinks she does. If they were trying to get revenge on her for murdering an innocent person or something she hopes they get away. But if they just went out looking for random people to hurt and got lucky, getting lucky doesn't make them not Evil.)