It's also possible that you're allowed to kill a vampire who has killed a mundane. As you've said, the Accords are supposed to govern that interaction.

Even if it was technically self-defense, I'm sure you didn't feel any regret. You killed a vampire, who you hate. Erika, who you dislike, is also dead. And now you're in a trial where the rest of us will be responsible for your death. This is the best possible ending for you.