"If you are against the bishop, who is the anointed one on Guam, then you are on the other side and not on the Church's side."
The GIRM is specific about this because, in the past, the time reserved for the homily was often abused by pastors to lecture their captive audiences on a pet peeve or something other than what was in the readings for the day, which is exactly what seems to have happened here.
So says St. Thomas Aquinas (1225-1274):
"There being an imminent danger for the Faith, prelates must be questioned, even publicly, by their subjects. Thus, St. Paul, who was a subject of St. Peter, questioned him publicly on account of an imminent danger of scandal in a matter of Faith. And, as the Glossa of St. Augustine puts it (Ad Galatas 2.14), 'St. Peter himself gave the example to those who govern so that if sometime they stray from the right way, they will not reject a correction as unworthy even if it comes from their subjects.... The reprehension was just and useful, and the reason for it was not light: there was a danger for the preservation of Gospel truth.... The way it took place was appropriate, since it was public and manifest. For this reason, St. Paul writes: 'I spoke to Cephas,' that is, Peter, 'before everyone,' since the simulation practiced by St. Peter was fraught with danger to everyone. (Summa Theologiae, IIa IIae, Q. 33, A. 4)
(It should be noted that "fraternal" and charitable correction was attempted many times by many people. The Archbishop has ignored it all.)"Some say that fraternal correction does not extend to the prelates either because man should not raise his voice against heaven, or because the prelates are easily scandalized if corrected by their subjects. However, this does not happen, since when they sin, the prelates do not represent heaven, and, therefore, must be corrected. And those who correct them charitably do not raise their voices against them, but in their favor, since the admonishment is for their own sake.... For this reason, according to other [authors], the precept of fraternal correction extends also to the prelates, so that they may be corrected by their subjects." (IV Sententiarum, D. 19, Q. 2, A. 2)
And look what St. Catherine of Siena (1347-1380) wrote to Pope Gregory IX:
"Most Holy Father,... because He [Christ] has given you authority and because you have accepted it, you ought to use your virtue and power. If you do not wish to use it, it might be better for you to resign what you have accepted; it would give more honor to God and health to your soul.... If you do not do this, you will be censured by God. If I were you, I would fear that Divine Judgment might descend on me....Alas, Most Holy Father! At times obedience to you leads to eternal damnation. (Letter to Pope Gregory IX, 1376.)
In the case of Archbishop Apuron, we have a prelate who publicly rejected a direct order from the pope as delivered by the Cardinal Prefect for the Congregation for Divine Worship and the Sacraments.