His own Canon law says it, as well as many canon lawyers (who told him so).
Listen marshmallow, Archbishop Lefebvre, and the bishops he consecrated were a few of the remaining churchmen that actually believe EENS and that hell is real. Do you really think that they would, (which the charge claims they did) do something with the intent of separating themselves from the Church? It's just absurd.
However, I do know this. The consecration of bishops is not something which can be separated from the Holy See. You know this. I know this. The people involved knew this. To consecrate bishops illicitly does separate you from the Church. If it doesn't, what does?
That's why it carries a latae sententiae penalty. Do it and you're doomed. It's nothing personal against SSPX. You weren't singled out for an extraordinary excommunication which is what you seem to be alleging. The same thing happened to Thuc at Palmar de Troya.