We need to be careful with the notion of "Ecclesia supplet"
Like every good canon lawyer, Fr. Francis Hoffman knows there is much more to the Catholic Church than canon law. Thus, in answering people's questions for Our Sunday Visitor's The Catholic Answer, Fr. Hoffman draws with equal facility on Sacred Scriptures, the Catechism of the Catholic Church, the Code of Canon Law, and a generally rich storehouse of ecclesiastical wisdom. I never fail to learn something by reading his column.
One of the things I like most is Fr. Hoffman's lawyer-like, straight-talk approach. He answers the question posed, and then sometimes elaborates, qualifies, or goes beyond the surface to comment on other things. A recent example (TCA, March/April 2007, p. 22) was Fr. Hoffman's correct response to a reader who wondered whether the absolution he received was valid, given that the confessor changed the words of absolution from "I absolve you from your sins" to "May God . . . absolve you from your sins." Fr. Hoffman told the reader that such an absolution was invalid. Now, who wants to tell people that their submission to the authority of the Church was invalid though no fault of their own? No one. But Fr. Hoffman had to give the correct answer, and he did.
My concern is not with Fr. Hoffman's answer but with an additional comment he offered at the end: "Nevertheless, the penitent's sins are forgiven because it was no fault of his own the priest used an invalid formula." Hmmm. Careful here. Continuing: "In this case, as sacramental theologians point out, Ecclesia supplet, that is, the Church provides, out of her treasury of grace, the proper remedy for the defect of the minister's actions." Maybe this is a quibble between canonists, but I'm not so sure.
I understand the concept of Ecclesia supplet (1983 CIC 144.1) to describe the Church's power to supply, under limited circumstances, jurisdiction for an act. But there is no question in this case about whether the confessor had jurisdiction; rather, what was missing were sacramental words, that is, some of the words which the Church holds to be necessary for validity of the sacrament. Since what was defective was sacramental form, I don't see how the Church's ability to supply jurisdiction helps our penitent. To adapt a phrase, Ecclesia non supplet quod Ecclesia non habet; the Church cannot supply what the Church does not have, and the Church does not have the ability to supply sacramental form to a minister's deficient utterance. Many historical examples of invalid baptisms, confirmations, or ordinations would seem to bear this out. Ecclesia supplet does not remedy those cases wherein innocent persons bore the consequences of ministers making invalidating changes in sacramental form, and I don't think it does so for confession, either.
So where does that leave our penitent?
Well, even though Ecclesia supplet seems of no avail here, nevertheless, we may hold that, in some way, Deus providet, that is, God provides, or God foresees. If tragedy were to befall a hapless penitent, I think, like Fr. Hoffman, that one's efforts to seek absolution for sins in this life would somehow be rewarded by God in the next.
But short of that, God provides in other ways, too, right here and right now. He provides by giving us priests like Fr. Hoffman who will tell it like it is and alert penitents that such absolutions are invalid; He provides by telling these penitents that, while He knows these mistakes were not their fault, He still expects them to act on their knowledge of the invalidity of such absolutions and return to confession (assuming we're talking about grave sins, etc.); and I even think He provides by giving the faithful the confidence to contact their confessors, and if necessary their bishops, to inform them of serious violations of the gift that is sacramental confession.
Meanwhile, the rest of us need to be wary lest we assume too quickly that Ecclesia supplet will remedy serious mistakes in ministry just because they were not the fault of the faithful. Salvo sapientiorum iudicio.