The Camoran dynasty was originally instated by the Aldmeri Dominion, we really only have the UESP's word for it that Haymon was a Bosmer, he could just as easily have been an Altmer or Ayleid (my personal favorite). While that wouldn't explain his Bosmer mother, the fact that Altmer are tall and Bethesda probably didn't want you looking down at the final villain does. Canonically speaking, he probably would have been a Bosmer.
That's a rather shaky asumption.
