Quick question has been really bothering me. Why did the USN Pilots NOT sink the IJN ships that were rescuing the survivors? After all, they were well aware, especially from Iwo Jima that IJN personnel were also being used to help supplement the IJA. By ensuring that there were no survivors, the invasion of Japan (A-Bomb was still a secret from general military personnel) would be made that much easier. Additionally, by sinking those IJN destroyers picking up the survivors, those ships would not be able to conduct convoy missions in the future.