I think that is the concept of "pool"....it is a pool of registars that all attack the deleted list as soon as it hits...which ever one gets it...get a cut with pool.com ....so...pool is like having a team of companies out there attacking the list for you....which ever one gets it...that is who your registar actually is.
I could be wrong, but that is what I think....reason being...one day I got 3 names.....each had a different registar....what fun! lol....but hey....at least I got the names I wanted.
Again....I could be totally wrong in my assumption....please correct me if you know something different.