A Cook County judge has ordered a new hearing in an unemployment benefits case because a state board relied on perjured testimony in its decision. In a 12-page order issued last week, Circuit Judge James M. McGing ruled that new information uncovered since the first hearing contradicted the referee’s findings that a worker was eligible for unemployment benefits. Dennis Del Valle worked for The Smithereen Co., a pest-control and extermination business based in Niles. In August 2012, he was terminated after the …