It was dark, and the light hadn't been right for L to have seen Kal's amused expression. If he had, he might have thought twice about shooting. What kind of person laughed at a gun when they were on decidedly the wrong side? As it was, though, he gave away his identity, which the man recognized and resented, before deciding to end his life with surgical precision. L was good at killing.
From L's perspective, of course, time didn't slow down. A gunshot was a fraction of a second, counting the recoil, reliable and violent but tempered by a practiced arm. No human's eyes were quick enough to follow a bullet. There was a sequence that a seasoned killer learned to expect from these types of encounters. Simplified, the sequence started with pulling the trigger, a shot, a red hole between the victim's eyes and maybe a messy exit wound in back, if range permitted, and then the lifeless target hit the ground. Logically, it confused L when the sequence ended halfway through, despite the fact that his shot was perfect to the millimeter. He paled as he saw something beyond explanation. Bullets broke skulls. Not the other way around. And then he was being mocked. He stared, the confidence gone from his eyes, lowering the smoking gun before his hand started to shake. He was pale, now. This was not fair. He was at a disadvantage.