It wasn’t really a failure of the intelligence community it was a failure of the Bush administration. Bush couldn’t believe his “friends” in Saudi Arabia would do anything to harm his administration, after all his family had had a long and profitable association with them for years.
Plus, at the time the Bush administration was up to its neck in scandals (anyone remember the Enron Scandal?). Bush’s popularity had cratered and it was looking increasingly like he would loose the midterms and Presidential elections.
Honestly, I can’t see how SCOTUS could rule in his favour. The US constitution clearly states that there is a seperation between church and state. For SCOTUS to rule in his favour would require them overturning the constitution itself.