His argument, which the court of appeals is likely to buy (because they really want to come up with a reason to deny the writ of mandamus) is that he did not deny the motion, he merely set it for hearing and gave groups who had previously been denied the right to file amicus briefs the opportunity to do so before the motion was heard.
Once the transcript of the call released, he looks even stupider. He ought to crawl in a hole and resign.