Okay... When he joined it was what 7 months old, had no product at all, they didn't even own the name and now it's the 9th most valuable company on earth. By the same token, if I start a company, you join the very next day, I don't do anything and you do all the work and provide all the money, you are not a founder.
If that's your definition then technically he's not a founder.
If that's your definition then technically he's not a founder.