The district court’s grant of habeas relief was affirmed where appellants’ petitions were based on the readback during jury deliberations of critical testimony without the knowledge or participation of the defendants or their attorneys. The district court’s factual findings – that the defendants and their attorneys were not informed of the readback, that the court reporter decided when to stop reading based on the reaction of the jurors, and that the trial court failed to control the readback – were not clearly erroneous. A defendant’s absence from readback proceedings is a trial error and subject to a harmless error review. Given the total lack of a record as to what happened during the readback, it cannot be discerned whether the error had a substantial and injurious effect or influence on the jury’s verdict, and therefore relief had to be granted.