yes, i believe it originally discovered the site through ballericons.com as you'll notice the link on one of the returned search result is to
http://www.rhinothumbs.com?var=baller which is the link code used on that site to link to rhinothumbs, that was the first one to make google. why is pageranking somehow affiliated with the site they find your site though or sites linking to you (ie if the site they found it though has a bad reputation, etc)?
interesting, thanks