I feel as though you guys must be looking at a different snake, ha ha! (I don't mean that as an insult -- I am just trying to see what you're seeing!)
I don't think I have ever seen a pewter that looked like that sire ... I could definitely see him as being a something (other than just pastel), but I just don't see pewter ..?
The original "odd" offspring has pewter traits that I can see, for sure, especially in that 2nd photo, and the triple baby sure looks a lot like a savannah pewter to me. I just don't see those same traits in the sire ...?? (I also don't really see cinnamon in the mother, either, but ..??)