Fact?! Since when?

Ron Moore, Executive Producer of the new Battlestar Galactica series on the SciFi Channel, blogs about evolution and the relationship to his characters trying to find Earth, the lost 13th colony (I added the emphasis):

"The question I would really like to see addressed is how to reconcile the underlying quest of Battlestar Galactica with actual scientific plausiability. The quest of Battlestar Galactica is to find Earth, the 13th Colony. However, it is a basic and well-substantiated tenet of science that human life here on Earth evolved slowly from a primate ancestor. Attempts to deny evolution based on the notion that human kind deserves a far more worthy origin than what evolution details, are a diservice to the pursuit of scientific truth and endeavors in our own world. There was always that reactionary sense to the original series, which drove it away from a secure standing as *science* fiction. How will the new series avoid this pitfall?"

I don't have a direct answer for this question yet. There are a couple of notions rolling around in my head as to how we reconcile the very real fact of evolution with the Galactica mythos, but I haven't decided which approach to take. However, it was a fundamental element of the orginal Galactica mythos that "Life here began out there..." and I decided early on that it was crucial to maintain it.

Uhm... since when has evolution been a fact? It's still referred to as the theory of evolution. It hasn't been proved. It can't be proved! No one was there to see it, and scientists can't recreate in their labs primates evolving into intelligent humans. Hence: theory.

Fact?! Since when?