SEO question about PR
 

Man i thought i had seen it all. this must jsut be some freak google error.

One of my affiliate links on my site is a pr7, meaning his affiliate link on my domain that i own is pr7. It makes no sense to me. He only links to it. His site is pr6. My index is pr3.

How is it possible that an affiliate link that is only linked from 1 domain give a page on my site pr7?

Possible, i've seen similiar, but never a PR7 (or 5 or 6 even)