How did Hinton learn about the results of his polygraph examination, and what were the results?

Hinton knew he had passed the polygraph examination because he heard a female guard talking to the examiner while he waited to be returned to C block. The guard had asked how Hinton did, and the examiner told her that the test showed Hinton was innocent. The examiner said Hinton showed no signs of deception and the test showed he did not commit the murders.