Cornwell washed out of seminary (I have no idea why) and appears to still be treasuring a grudge against the Church on that account.
He has written quite a number of frankly anti-Catholic books, and his latest is a book trashing Pope John Paul II.
That will no doubt make him even more popular among the anti-Catholic crowd.
Please remember that I am not anti-Catholic, I am pro God. I'm not anti-Protestant or anti-Jew or anti-Orthodox or anti-Mormon either, btw.
I assert that to whatever extent the Pope may have failed in the WWII era and his memory suffered since - it could be a Spiritual matter and if so, beyond the ability of mere mortals to repair.
In sum, if he truly believed that the gates of Hell cannot prevail against the Church then he should have had no concern whatsoever that the parochial schools would be closed or public worship stopped in Germany. He should have had no fear of arms or politics whether Nazis or Communists. He should not fear Protestants for that matter or any mortal or supernatural power except God Himself.
IOW, if the act of signing a Concordant was for fear then it would have constituted a statement of disbelief. Further, I assert that God deals harshly with the ones who disbelieve Him especially those who are leaders.
Conversely, when one believes God, especially under duress, Gods protection remains. Joshua and Caleb, for instance, were not fearful of the inhabitants of the promised land whose mortal strengths were many. Instead, they believed God and for that reason they alone were allowed to enter there 40 years later while all those who disbelieved died in the wilderness.
[Let your] conversation [be] without covetousness; [and be] content with such things as ye have: for he hath said, I will never leave thee, nor forsake thee. So that we may boldly say, The Lord [is] my helper, and I will not fear what man shall do unto me. Hebrews 13:5-6
I will love thee, O LORD, my strength. The LORD [is] my rock, and my fortress, and my deliverer; my God, my strength, in whom I will trust; my buckler, and the horn of my salvation, [and] my high tower. Psalms 18:1-2
Woe to the rebellious children, saith the LORD, that take counsel, but not of me; and that cover with a covering, but not of my spirit, that they may add sin to sin: That walk to go down into Egypt, and have not asked at my mouth; to strengthen themselves in the strength of Pharaoh, and to trust in the shadow of Egypt! Therefore shall the strength of Pharaoh be your shame, and the trust in the shadow of Egypt [your] confusion. Isaiah 30:1-3
It stands to reason that scholars would want open access much like attorneys would want answers to their interrogatories or requests for documents even if they stand as advocates for one side or the other. In the absence of full disclosure, any objective third party observer would have just cause to question the results of the inquiry.
However, if the Concordant was a statement of disbelief as I wonder here - and the dishonor which followed was according to Gods will - then no mortal will be able to undo it. So the Church will have to live with it - and in such cases it is best to let a sleeping dog lie.
Any hoot, that's my "two cents"...