Puleeeze.
I just finished an excellent book, Paul Revere's Ride, 1994, by David Hackett Fischer. Using all available sources, including depositions -- of both American and British soldiers in the battle -- taken days after the atttacks on Lexington and Concord, he concludes that it is impossible to say who (on which side) actually fired the first shot. It seems that the first shot was fired by someone other than those in the ranks of British Regulars or the Minutemen, who were facing each other about 50 yards apart on Lexington Green as dawn broke on 19 April, 1775.
It is only clear that the first volley was fired by the Regulars at the Minutemen, without any orders to fire from the British commander of that unit. Applying that analogy to the attack on Pearl Harbor, whoever fired the "first shot" is irrelevant. It was the first volley that committed both nations to war. And the first "volley" at Pearl Harbor was the first wave of Yamamoto's Zeros which attacked the American warships.
Congressman Billybob