That’s cause he’s wrong. LiDAR is less effective when there is water (in this case vapor) to scatter the lasers but it’s way better than an optical camera and in turn way better than an eyeball.

Ironically, most self driving cars use LiDAR so fog wouldn’t affect them. Only Tesla relies solely on optics.

Edit: to stop the pedantics below, water vapor in the air can affect LiDAR, it still functions though and considerably better than a human or an optical camera in fog.