“I believe he is a party in this action.”
Don’t think so. He is not harmed in any way regardless of the Appeals Court ruling, so he has no standing. He is AFFECTED by the rule, but the ruling involves how he judges. It is as if the Appeals Court required him to allow a certain piece of evidence. He could not appeal that, although the prosecutor or defendant could.
He is formally a party. He is the defendant in Powell’s special legal suit filed with the appellate court. The appellate court ruled against him and ordered him to dismiss the Flynn prosecution.