Piebald has nothing to do with inbreeding. It is all about gene expression.
http://en.wikipedia.org/wiki/PiebaldBone, it also mentions in that article that because it has to do with a skin pigmentation allele that the eyes can and will reflect the color of the skin around it. I looked back at the pictures and it has dark skin around the eye, maybe it has lighter skin in close to the eye we can't see.

Also in the article it says that magpies get their name from the black and white coloring, and also the bald eagles name is derived from the contrast of white head and dark body!
Brandon