[ultima ratio]

A source: the Catholic Encyclopedia:

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An excommunication is said to be null when it is invalid because of some intrinsic or essential defect, e.g. when the person inflicting it has no jurisdiction, when the motive of the excommunication is manifestly incorrect and inconsistent, or when the excommunication is essentially defective in form. Excommunication is said to be unjust when, though valid, it is wrongfully applied to a person really innocent but believed to be guilty.

[gbcdoj]

Excommunication is said to be unjust when, though valid, it is wrongfully applied to a person really innocent but believed to be guilty.

Isn't this the case you propose? "the pope can be wrong in his judgment". Certainly the Pope had jurisdiction, there was nothing wrong with the form of the declaration, and the motive was not manifestly inconsistent (schism), nor manifestly incorrect (Msgr. Lefebvre was widely considered to have created a schism by his actions).

[Mershon]

Isn't it interesting that ultima NEVER replies to the authoritative decrees from gbcdoj?

Never. In fact, the Catholic Encyclopedia, and your interpretation of the citation you cited is NOT more authoritative than the Pope's encyclical that GBCDOJ cited, nor Ecclesia Dei Adflicta.

Ultima, nor anyone else for that matter, EVER responds to G's authoritative citations, always from TRADITIONAL sources as well. Nearly everyone else just repeats "ad nauseum" the SSPX propaganda.