Robert Tebbens sued Levin & Conde and three of its attorneys for alleged malpractice when representing him in a divorce case, but the defendants — invoking a defense that, the Illinois Appellate Court acknowledged, is subject to “some disagreement” — insisted res judicata barred the lawsuit because Tebbens raised the same set of objections during an unsuccessful challenge to the firm’s petition for $42,345 in fees.After the judge in the dissolution case ordered Tebbens to pay these fees as …