The same Code states that, under paragraph a, the person must have KNOWINGLY lied. NO soup for you, Fitz! The WH did the search for the email
Yes, and not only would Rove have to have "knowingly" made a false statement, but the false statement must be "material" to the subject matter of the investigation.
If it were definitively established that Rove did not know Plame was a "covert" agent or that her status was classified, then arguably it is not "material" when or how Rove made the statements to Cooper about her, since Rove's statements could not amount to a crime in any event.