The Marine pilots who managed to shake off the Zeros used high speed split-s turns or very steep dives. These maneuvers were later found to be the best means to evade pursuit by the highly maneuverable Japanese fighters. One F2A-3 pilot, Marine Captain William Humberd, dove away from his pursuers, then attacked a Zero in a head-on pass, shooting his opponent down. In the battle, some F2A-3s suffered from inoperative guns. The nose-mounted guns' occasional failure to fire was noticed by other users as well; the phenomenon may have been caused by frayed electrical wires in the mechanism that synchronized the nose guns with the propeller. Other Buffalos had not been fitted with plate armor behind the pilot, making them vulnerable to even a single bullet or shell. Losses were aggravated due to the Japanese practice of strafing pilots who had bailed out. Second Lt. Charles S. Hughes, whose Buffalo was forced to retire at the start of the raid due to engine trouble, had a ringside view of the aerial combat: