I would imagine Pool would get the money. The domain registrar and affiliate referrer, if there was one, would also get a percentage. Wouldn't that be nice! :o
Pool has arrangements with a bunch of registrars that are all in the hunt for dropping domains. If one of the registrars catches the domain on behalf of Pool, the final bid price for the name is split (50/50?) between Pool and the registrar.
I'm unsure that this information is publicly available, to be honest ... the exact relationships and business arrangements between Pool and their varying partner Registrars.
Have you tried E-mail'ing Pool for this information, or would you like me to try?
Thanks.