His name was Pinchas Lapide and he was a Canadian Jew, a British soldier in the Second World War (178th Transport Company, 8th British Army) and an Israeli diplomat and historian. His book is called Three Popes and the Jews.
You wrote:
“lol. Right. A man, no doubt, who has nothing to lose by criticizing Rome.”
What would he have to lose? First of all, he was mistakenly called the Israeli ambassador to Italy. Let’s say he was that. That’s Italy, not the Vatican. Second, he was actually consul to Milan, and not the Israeli ambassador to Italy. Also, he had looked to Pius XII as a hero since WWII so the idea that he came up with the 860,000 number out of thin air to stop from losing something as you so ignorantly asserted without any evidence whatsoever is just plain nonsense.
Thanks for the correction, vlad.