"I think that Martin Luther’s intentions were not mistaken; he was a reformer. Perhaps some of his methods were not right, although at that time... we see that the Church was not exactly a model to emulate. There was corruption and worldliness in the Church; there was attachment to money and power. That was the basis of his protest. He was also intelligent, and he went ahead, justifying his reasons for it.The Pope will also commemorate the 500th anniversary of the Reformation on 31 October in Lund, Sweden (see here).
Nowadays, Lutherans and Catholics, and all Protestants, are in agreement on the doctrine of justification: on this very important point he was not mistaken."
Since the beginning of this pontificate, the Pope has used these in-flight press conferences as a testing ground and 'early-warning system' for his 'innovations' (i.e. communion for practicing adulterers, normalization of homosexuality, women deacons, ...). So I'm willing to bet that the Lund event will be a sort of 'canonization' of Luther with the active blessing of the Pope.
But there is only one minor problem concerning the efforts to rehabilitated Martin Luther. The fact is...
...Martin Luther was completely mistaken. In fact he was a bit more than wrong; he was a condemned heretic!
Pope Leo X, expressly condemned the errors of Martin Luther in the Bull Exsurge Domine of July 15, 1520. It formally condemned forty-one propositions drawn from his writings, ordered the destruction of the books containing the errors, and summoned Luther himself to recant within sixty days or receive the full penalty of ecclesiastical punishment:
"By the authority of almighty God, the blessed Apostles Peter and Paul, and our own authority, we condemn, reprobate, and reject completely each of these theses or errors as either heretical, scandalous, false, offensive to pious ears or seductive of simple minds, and against Catholic truth. By listing them, we decree and declare that all the faithful of both sexes must regard them as condemned, reprobated, and rejected. We restrain all in the virtue of holy obedience and under the penalty of an automatic major excommunication".Several of condemned propositions concerned Luther's doctrine of justification (i.e. 1-14, IMHO).
Not only did Pope Leo X condemned several propositions concerning Luther's doctrine of justification, but the Sacred and oecumenical Council of Trent, sessions VI and XIV anathematized all the tenets of the said doctrine (see, inter alia, Session VI - Canons IX,XII, XIV, XIX and Session XIV - Chapter II).
I would argue, based on the way in which Pope Leo X and the Council of Trent expressed their condemnations of Luther's doctrines, that to say that Martin Luther's doctrine of justification is "not mistaken" is to say that the Church's infallible magisterium is wrong.
Besides proving, beyond a shadow of a doubt, that the Church has thought that Luther's doctrine of justification is indeed mistaken, it is also important to show why it is so.
The doctrine of justification: Martin Luther Vs Catholic Church
The Catholic Encyclopedia's article on Sanctifying Grace summarizes the differences between Luther's and the Catholic doctrine of justificaton. The author of this article is the Rev. Joseph Pohle, S.J. (who also authored the Pohle-Preuss Manual of Dogmatic Theologya, available at archive.org).
I tried to express the whole argument in SmartArt form (I like diagrams):