Troy, I think you're thinking of the Pacific Strategy Conference at Hawaii in Jul 1944.
WW2DB: Pacific Strategy Conference
At that conference, he upstaged Roosevelt (not Truman) by arriving fashionably late, and fielded a motorcade bigger than the president's, or something along those lines -- my memory is failing me slightly tonight on the details
He wasn't "sacked" until Korean War. Sure he was not perfect, but he was definitely the scapegoat for the war not going as well as the White House wanted. Truman cited the excuse of his "un-cooperativeness" with his commander-in-chief as one of the reasons for his removal.
WW2DB: Douglas MacArthur
MacArthur left Japan on 16 Apr 1951 after he got the "sacking" order. That morning 250,000 Japanese lined the street at 0630 to say goodbye to their respected former SCAP, General "Makassar". Signs said "We Love You, MacArthur", "With Deep Regret", "Sayonara", and "We are Grateful to the General". His ticker tape parade in Manhattan had a greater turn-out than Eisenhower's. The people loved him as a hero. The politicians hated him because he had the potential to beat them at their game.