All we can offer is opinions. In this hobby, there is no one voice to rule them all. You may talk to a breeder tomorrow who grades his hets and poss's completely differently than anyone you've ever met, but it's what makes sense to him. He should be willing to explain his system, that's all anyone can ask. That's just a fact of life-- no one will ever see exactly eye to eye with everyone else. Everyone perceives differently.
And that breeder would be wrong. This is a mathematical probability, it's not open to interpretation. That's like saying two plus two equals three because that's what makes sense to me...