Time to
i n t e r r o g a t e

Let's see... hunting an adult Y'vakkon and knowingly harming innocent bystanders... in the process in front of said Y'vakkon... he's hosed.

But he is bound and not a threat at this point... killing him would be a gray area because it can't be said it was done in self-defense. I think the guy better start singing like a bird and hope station security doesn't turn their backs because they don't want to deal with the paperwork him being alive would impose on them.

He's got diplomatic immunity, and was attacked. I think the answer is 'legally, you could, but it would look better to let him live, at least for now, and persuade him to answer questions about his sponsors.'