Why has a gray cat become a problem for Tesla?

On October 3, Musk mentioned a specific challenge: in the dark, avoiding a gray kitten on a gray road surface. That Austin Robotaxi service extended its end time from 10 p.m. to 11 p.m. The real difficulty is low light and low contrast. The image information available to cameras decreases, while active ranging can supplement 3D geometric information. Waymo's nighttime demonstration showed the role of multi-sensor fusion, but it cannot be concluded from this that Tesla has changed course. Whether the limited-time operation is intended to save on remote human night shifts is still only speculation. What really needs to be verified is how the system maintains safety under these difficult conditions.