A few comments: Cardinal Biffi's assessment of a grave distortion of the Gospel at the most fundamental level is exceedingly mild.
The "contemporary German author" Cardinal Biffi has in mind is likely Jürgen Moltmann, although, it could be any given German Cardinal or Bishop, or a certain German Pope who is in the habit of reckless statements and acts that betray an ambivalence towards the Gospel at best.
This is useful information but in the big picture it seems to be a limited hang-out for English speakers. Could Cardinal Biffi be unaware of his neighbor, Cardinal Carlo Maria Martini's, L'assurdo di Auschwitz e il Mistero della Croce and many other such works? Could he be unaware that one of John Paul II's first papal acts was to offer a Mass at Auschwitz and proclaim, "I kneel at this Golgotha of the modern world"? Does this not at least represent a grave alteration of Christology fatally compromising the whole perspective of "sacred doctrine"? Dual-covenant ("Noahide") theology and the Calvary-relativising theology of Auschwitz are tightly intertwined within the contemporary German school of philosophy/theology that Biffi makes reference to which John Paul II and Benedict XVI were certainly influenced by.
That such violence to the Gospel could be excused as a concession to "Jewish-Christian dialogue" only demonstrates the problem inherent to that "dialogue."
... AN UNPRESENTABLE CHRISTOLOGY
At the end of October 1991, [Vatican II peritus, Fr. Giuseppi] Dossetti graciously brought me the speech I had commissioned from him for the centenary of Lercaro's birth. "Examine it, change it, add, remove freely," he told me. He was certainly sincere: at that moment, the man of God and faithful priest was speaking.
Unfortunately, I found something that wasn't right. And it was the idea, presented favorably by Dossetti, that just as Jesus is the Savior of the Christians, so also the Torah, the Mosaic law, is also currently the path of salvation for the Jews. The assertion was shared by a contemporary German author, and was probably favored by Dossetti because he saw its usefulness for Jewish-Christian dialogue.
But with chief responsibility for orthodoxy in my Church, I could never have accepted putting into doubt the revealed truth that Jesus Christ is the only Savior of all. [...]
"Fr. Giuseppe," I said to him, "haven't you ever read the pages of Saint Paul, and the narration of the Acts of the Apostles? Doesn't it seem to you that in the first Christian community, the problem was exactly the opposite? In those days, it was accepted peacefully and without a doubt that Jesus was the Redeemer of the Jews; if anything, what was discussed was whether the gentiles could also be fully reached by his salvific action."
Besides, it should be enough – I thought to myself – not to forget a little phrase from the letter to the Romans, where it says that the Gospel of Christ "is the power of God for the salvation of everyone who believes: for Jew first, and then Greek" (cf. Rm. 1:16).
Dossetti was not in the habit of renouncing any of his convictions. Here in the end he gave in when I warned him that, if necessary, I would interrupt and publicly contradict him; and he acquiesced to say only this: "It does not seem consistent with the thinking of Saint Paul to say that the way of salvation for Christians is Christ, and for Jews is the Mosaic Law." There was no longer anything erroneous in this statement, and I did not raise any objections, even if I would have preferred that there had not even been a reference to such an aberrant theological opinion.
This "incident" made me reflect a great deal, and I immediately judged it to be of extreme gravity, although I did not speak of it with anyone at the time. Any alteration of Christology fatally compromises the whole perspective of "sacred doctrine." In a man of faith and of sincere religious life like Fr. Dossetti, it was plausible that the misstep was the result of a mistaken and inexact general methodological approach ... ("Cardinal Biffi Breaks Another Taboo. On Dossetti," Sandro Magister, Chiesa, January 3, 2011)
Vatican II Peritus: Because of "The Holocaust," Church Must Reinterpret Gospel