Since you said the bet was void is one of you was scum, that means you're not really risking anything if you're scum.
I find your theory that brain and RHK were teammates so implausible that it's very hard to believe you believe it. Brain is most likely town, there's a chance he could be 3P, but getting into a double Doctor claim with RHK on D3 makes so little sense. It's not like brain gains eternal towncred for that, so what would be the point? If the idea was to sacrifice brain so that RHK gained towncred, why would RHK react to brain's claim the way he did?
It makes no sense no matter how you look at it. And the crumbs of Interceptor from brain you supposedly saw were not convincing at all.