While it is true that MacAuthur went into a funk and did little for several hours following the news the US was at war it really made little difference. It was primarily his chief of staff, General Sutherland, that caused the initial disasters to occur.
It was Sutherland that overrode MacAuthur's air commander Brereton on putting up standing air patrols. Sutherland also overrode Brereton's wish to immediately launch a B-17 strike on Formosa. Instead, Sutherland demanded Brereton perform reconnissance of Japanese bases and then wait until those results were available to launch a strike.
Sutherland also overrode Brereton's alternate suggestion to move the B-17 force to Mindinao until the reconnissance was complete to keep them out of range of Japanese attacks.
Sutherland can be held to be the incompetent that foremost cost the US their air force in the Philippines. His continued meddling with US air operations likewise was largely the cause of failure in New Guiena until General Kenney showed up and stood up to him.