In his 1948 book on Big Game hunting he lists "the 270 Win is probably the finest small caliber commercial load made today" and other comments about its superiority for long range deer/sheep/goat hunting repeatedly. Yeah he himself hunted with different rounds but he definitely gave the cartridge its due even though it wasn't one of his favorites.
The whole 270 thing with Elmer, was just his way of a Dig at JOC. There was no lost love between those two.
