It is very interesting what Msgr. Williamson says regarding the ambiguity in the new rite of episcopal consecration (at 1:16:24 - 1:18:01), and the sedevacantist accusation of invalidity.

He notes the principle significatio ex adjunctis (or as Msgr. Williamson states it, determinatio ex adjunctis), which basically says in sacramental theology "an ambiguity is settled by immediate context."  Meaning, it is conceded that "spiritus principalem" is ambiguous.  Nevertheless, the immediate context removes the ambiguity where the word bishop (episcopus) closely follows.  The conclusion therefore, is that, as the ambiguity does not survive, the form is valid.

Explaining this principle, he cites Michael Davies' book The Order of Melchisedech, which in turn cites Fr. Francis Clark in Appendix I:

"The sacramental signification of an ordination rite is not necessarily limited to one phrase or formula, but can be clearly conveyed from many parts of the rite.  These other parts could thus contribute, either individually or in combination, to determining the sacramental meaning of the operative formula in an unambiguous sense.  Thus the wording of an ordination form, even if not specifically determinate in itself, can be given the required determination from its setting (ex adjunctis) that is, from the other prayers and actions of the rite, or even from the connotation of the ceremony as a whole in the religious context of the age." 
-The Catholic Church and Anglican Orders, F. Clark, S.J.  (CTS, 1962), p.21.

Yes, I thought that was interesting as well. I don't recall ever having heard of ambiguity being settled by context, but it makes some sense.

However, I don't understand how this relates to the subject of Anglican orders. Perhaps you can explain?

"The sacramental signification of an ordination rite is not necessarily limited to one phrase or formula, but can be clearly conveyed from many parts of the rite.  These other parts could thus contribute, either individually or in combination, to determining the sacramental meaning of the operative formula in an unambiguous sense.  Thus the wording of an ordination form, even if not specifically determinate in itself, can be given the required determination from its setting (ex adjunctis) that is, from the other prayers and actions of the rite, or even from the connotation of the ceremony as a whole in the religious context of the age." 
-The Catholic Church and Anglican Orders, F. Clark, S.J.  (CTS, 1962), p.21.

I thought that there were other reasons for the invalidity of Anglican orders, but can't recall them just now. I doubt that +W himself would make a case for the validity of Anglican orders, or that he meant to do so at all, if that's what you're getting at.

I hope that you understand my confusion in this matter, since the subject of Anglican orders does not come into the subject matter at all, regarding the content of the video featuring Bp. Williamson. Therefore, I assume that Fr. Clark's view of the matter was not impressed upon Bp. Williamson's view.

It is very interesting what Msgr. Williamson says regarding the ambiguity in the new rite of episcopal consecration (at 1:16:24 - 1:18:01), and the sedevacantist accusation of invalidity.

He notes the principle significatio ex adjunctis (or as Msgr. Williamson states it, determinatio ex adjunctis), which basically says in sacramental theology "an ambiguity is settled by immediate context."  Meaning, it is conceded that "spiritus principalem" is ambiguous.  Nevertheless, the immediate context removes the ambiguity where the word bishop (episcopus) closely follows.  The conclusion therefore, is that, as the ambiguity does not survive, the form is valid.

Explaining this principle, he cites Michael Davies' book The Order of Melchisedech, which in turn cites Fr. Francis Clark in Appendix I:

"The sacramental signification of an ordination rite is not necessarily limited to one phrase or formula, but can be clearly conveyed from many parts of the rite.  These other parts could thus contribute, either individually or in combination, to determining the sacramental meaning of the operative formula in an unambiguous sense.  Thus the wording of an ordination form, even if not specifically determinate in itself, can be given the required determination from its setting (ex adjunctis) that is, from the other prayers and actions of the rite, or even from the connotation of the ceremony as a whole in the religious context of the age." 
-The Catholic Church and Anglican Orders, F. Clark, S.J.  (CTS, 1962), p.21.

Nah, the NO Rites of Consecration and Ordination have defective form, and so this notion of ambiguity does not apply.

How does one validate a desacralized liturgy?

According to Chiesa Viva's analysis of Bugnini's masonic correspondence to his co-conspirators, the Novus ordo missae's Offertory contains a verse from the Kabbalah.  The purpose was to desacralize the mass.