Here is a video of the accident between Lewis Hamilton and Kimi Raikkonen. Lewis Hamilton retired on lap 20 after his pit stop during the Safety Car period, when he hit Kimi Raikkonen’s Ferrari at the pit lane exit who had stopped. While you can clearly see Nico Rossberg’s tail light flashing red (indicating that he is braking), Kimi’s light is not flashing at all, even though, he is clearly slowing down before reaching the while line, not sure why this happened, but it might be that Hamilton did not notice Raikkonen stopping.