Not sure I understand this -- are you saying the judge took the PO rubber-stamp as proof that though the prior art might be related, it was not disqualifying?
I'm not a patent lawyer, but I've been involved in this stuff, often conducting extensive prior art searches. The gold standard for prior art is a single document that teaches everything in the claims of the patent. Often, folks think that they've found prior art if they find one thing in one document and another thing elsewhere. Nope.
Now if you happen to find the pieces of a claim in different prior documents, then you may be able to demonstrate obviousness rather than prior art. For instance it's generally considered obvious to take two patented ideas and combine them together. But obviousness is profoundly harder to prove than straightforward prior art.
Meanwhile, anything that's taught in the body of the patent, can be added to the claims at a later date. Within some limitations of course. A patent can be invalidated in its entirety, and the holder can submit a completely new claim set based on the original body text.
> Often, folks think that they've found prior art if they find one thing in one document and another thing elsewhere. Nope.
Still, I think there must be something profoundly broken if you find the exact math in an old book, and the new patent basically says, "do that math on a computer".