Macdonogh was distrusted by Haig and Haig's intelligence adviser John Charteris, with whom he had an acrimonious correspondence. He presented figures to the War Cabinet in October 1917, pouring cold water on Haig's predictions that German manpower would be exhausted by the end of the year. An infamous entry in Haig’s diary (15 October 1917) mentions that MacDonogh "is a Roman Catholic and is (perhaps unconsciously) influenced by information which reaches him from tainted (that is, Catholic) sources". He also predicted the date, time and location of the German March 1918 "Michael" Offensive, as did Charteris.