First and foremost its a crime to lie under oath.I don't think you have understood my question. Why did he have to admit that?
He and his lawyer had told the court that he had no texts or emails discussing Sandy Hook and certain things with financials etc. It proved that he was lying to the court and completely discredits him as a witness to the jury.
He had to admit it wasn't a hoax because if he didn't he would be in contempt of court.