Re: "...a [Lidar] blind spot low to the ground all around the car."
Similarly, most vis sensors are not actually vis, they stretch into near IR so there should have been no issue with the pedestrian having dark clothing
1. A lot of cameras have an IR filter to keep infrared from reaching the sensor. Since the focus point for IR is different than for visible light, getting a clear image is enhanced by blocking the out of focus IR,
2. A visible light sensor may pick up near IR, it will not pick up far IR - generally such sensors, used in missiles, need to be cooled significantly to function, often with liquid nitrogen. Far IR is from 8 to 100 microns, and the peak emissions from the human body are at 9.3 microns. Unless the car has IR floodlights, near IR is no better than visible light with no lights.