In The Hobbit: An Unexpected Journey, Thorin's company comes to Rivendell. While there, Elrond, Galadriel, and Saruman privately brace Gandalf to inquire about his activities with the dwarves. (~1h35m)
Gandalf argues that Thorin's personal quest to reclaim Erebor will have a larger strategic benefit: the dragon Smaug is a likely ally of "the enemy" (Sauron), so it's better to dispense with it now.
Saruman insists that Sauron is permanently crippled and can never pose a threat, and is pretty quick to discount the few pieces of evidence presented.
Knowing that he later throws in completely with Sauron, I have to wonder: is Saruman's behavior at this meeting simply genuine skepticism, or is he already turned and knowingly undermining his evil master's enemies?