As much as I like Riley, he really can't be Ash's father. He looks way too young to have had a ten year old kid running around. Personally, I never really cared about finding out who Ash's father is and I don't think it's really that important for him to appear or to have some important role. He could just be traveling around aimlessly for all we know and it wouldn't really have an impact on the series or Ash's character.

