How was a man of the sanctity, humanity and intelligence of Ronald Knox capable of saying this about the murder of thousands of people?

Theologically speaking, my thesis is that it would have been a more perfect thing not to bomb Hiroshima. Or, if I must needs talk the language of common life, let me dig up a phrase from an almost forgotten, but not wholly unregretted past, and say that bombing Hiroshima was not cricket (God and the Atom, chapter V, 1945).

Truly, war does strange things even to the best men.