That's from before Ratzinger offered the Aug. 15th consecration. Look at the date of that Conference - it was less than a week after May 5, whereas the offer came after May 20th, when Ratzinger offered to expedite the consecration.
Of course, having only Msgr. Lefebvre's version may mean that it's distorted as well - he had a poor memory especially as he aged (for instance, his denial that he signed the texts of "Dignitatis Humanae" and "Gaudium et Spes"), and other parts of that same Conference are clearly incorrect in light of the actual documents he refers to (oddly, he gives as quotes what are in fact inaccurate caricatures of the documents):
Indeed, in that letter - I do not have it here - which he brought me from the Holy Father , there is an astonishing sentence. It goes, "It is possible that we consider one day granting you a consecration," as if it was something very vague, a mere possibility, an eventuality. I cannot accept that.
What he refers to is apparently this:
Lastly, I wish to express my gratitude for the intention that you manifested to take into account the particular situation of the Society, proposing to nominate a bishop chosen from its members, and especially in charge of providing for its special needs. Of course, I leave to Your Holiness the decision concerning the person to be chosen and the opportune moment. May I just express the wish that this be in the not too distant future?
None of what you say belies the fact that the secretary's grotesque letter--the one purportedly composed by the Archbishop in which he owns up to his own supposed "errors", makes no mention of any definite date. The "iffy" tone of it underscores the truth of what Lefebvre maintained. It reduces what should have been something definite into something merely proposed. It also leaves the name and date up to the Pontiff--maybe--if the Pontiff so wishes! You prove my point! There is no mention of August 15. If it had been as definite as you suggest, where is mention of it?
You talk about the Archbishop's memory. In fact, it was pretty darn good--though he was speaking informally, without letters at hand. But he got the jist of what was happening--he was being given the runaround. The secretary's final letter proved this--and made it clear all the rest was to string him along. But the matter was too important for this to be left up in the air and not pinned down. The Pontiff was hostile to Tradition and would know a loophole when he saw it--just look at how he betrayed the FSSP ten years after his motu proprio promised the Fraternity its priests might use the '62 missal exclusively.
I haven't followed your debate on the Lefebvre consecrations very closely, but ultimately the issue comes down to this: Was Lefebvre paranoid, imprudent, disloyal, etc. to doubt the word of the Vatican that they would approve an episcopal consecration in the future.
One could validly take either side of that argument, but let me offer this bit of evidence regarding trusting the Vatican's word about future episcopal consecrations: It has been 16 years now, and where is the bishop for the FSSP? According to the Vatican view, the Fraternity IS the SSPX, the loyal SSPX who stayed with the "barque of Peter," the ones who continued the SSPX defense of tradition but within the structure of the Church. So where is their bishop? Haven't they been waiting all these years? Don't they have a seminary in the US (in addition to one in Europe) with more seminarians than a dozen US dioceses combined? Why don't they have a bishop to ordain those seminarians? Aren't they opening parishes, saying the Latin Mass around the world, including in Africa, and defending the traditional Catholic faith in a time of crisis when so many bishops and dioceses are in open apostasy? So why don't they have a bishop to lead them in these activities? When new auxiliary bishops are appointed every week to help destroy the faith in apostate dioceses, why has the Fraternity of St. Peter had to wait 16 years with no end in sight?