I don't think there is any proof that he did any of this for humanitarian reasons. He did short his troops on Bataan by doing that though.
That he supplied the 25K-25K refugees and residents of Bataan from the meager provisions is evidence for humanitarian motives. As for political reasons:
"When it became obvious shortly after the Japanese landings that Luzon might soon come completely under enemy control, the increasing objection of the Commonwealth Government to measures that might reduce the food available to the Philippine public under Japanese occupation handicapped further accumulation of food reserves. This objection was reflected in the frequent refusal of Headquarters, USAFFE, to approve the commandeering of food, even the seizure of stocks owned by Japanese nationals."Stauffer, Aliv P., "United States Army in World War II ,The Technical Services, The Quartermaster Corps: Operations in the war against Japan", Center of Military History, United States Army, (p9), 1956