The ACA had argued that issues like who was a member in good standing of the parish were ecclesiastical and up to the parish rector and the bishops of the ACA. The bishops, in an effort to reverse several parish votes in favor of joining the Patrimony of the Primate, the US Catholic Ordinariate, and disaffiliating from the ACA, had argued retroactively that no such vote could be valid, because it was up to the bishops to determine who was a member eligible to vote, and basically if you wanted to leave the ACA, you had abandoned communion, so your vote wasn't valid. So the only valid votes basically would be from those who wanted to stay in the ACA -- and the First Amendment prevented the courts from intervening in this ecclesiastical issue.
The actual record made this tenuous, as the story came out in oral arguments. The parish bylaws required that a list of members in good standing eligible to vote be drawn up by the rector in January and July of each year, and that the list be posted. Neither the ACA nor the St Mary's dissidents ever registered any objection to this list. Prior to the July 2012 vote to disaffiliate from the ACA, Anthony Morello notified exactly two members of the parish that they had been excommunicated -- but with an 80% vote in favor of disaffiliation, this had no effect on the landslide outcome of the vote. The elected vestry's attorneys argued that this was sufficient to decide the issue, and no ecclesiastical judgment was involved.
Based on the questions by the appellate judges during arguments, my wife and I got the impression that the judges were leaning toward the elected vestry's position on this matter: they appeared to believe that several actions by Bishop Strawn and Anthony Morello were unauthorized by either the parish bylaws or the ACA canons (a position my wife and I have held all along).
Naturally, it ain't over til it's over, but it was good to have a breath of sanity in these proceedings.
