Case precedent in the court states knowingly looking something up illegal or not, is *not* illegal.
What case in what court? Because the case you cited before pretty much says that under the statute in question that knowingly looking at something illegal is illegal. One court in one jurisdiction might rule one way and another court in another jurisdiction might rule the other way, and unless one of those courts is in your jurisdiction and of higher authority than your court you can't really tell in advance which rule applies to you.