"even the alleged 'necessity' was deliberately created by Archbishop Lefebvre in order to preserve a posture of separation from the Catholic Church"
What hogwash. Aren't you embarrassed to post such nonsense? Canon 1323 says its up to the individual to decide whether a necessity exists or not. If he decides it does--then there can be no automatic excommunication. That's the law. No amount of second-guessing can erase it. If the Pope had a problem with that, he had every right to convene a tribunal and make formal accusations. He did not. So the canon stands.
In fact, the charge is a blatant smear. The Archbishop not only believed there was a necessity, he wrote about it, he complained loudly to Rome about it, he was interviewed by the press for years about it. There can be no doubt whatsoevr of his honesty in this matter.
What is shocking is the extent to which the Pope's defenders will lie to themselves to twist reality and pretend somehow that the Archbishop was insincere when clearly he was not. He had argued over and over he must preserve the ancient Mass since it was the primary vehicle for transmitting the ancient faith. That this should be so airily dismissed says a lot about Rome's lack of faith these days--and a lot about this Pope.
Can. 1325 Ignorance which is crass or supine or affected can never be taken into account when applying the provisions of cann. 1323 and 1324.
When ignorance is deliberately aimed at and fostered, it is said to be affected, not because it is pretended, but rather because it is sought for by the agent so that he may not have to relinquish his purpose. Ignorance which practically no effort is made to dispel is termed crass or supine. (Catholic Encyclopedia, "Ignorance")