Maybe Nebo has some racing line in his pedigree. I've seen other examples of different looking coats in the same breed.

http://www.workingpitbull.com/amstaffpit.htm

It mostly talks about the differences in Pit Bulls and AmStaffs, but at the bottom of the page it shows the differences in show bred English Setters and field working English Setters, as well as Huskies.

The show bred Setters are bred to look pretty while the working Setters are bred for their working abilities rather than a pretty coat. Before the AKC came into play, a lot of our breeds probably weren't as pretty as they are now.