This test lacks realism.

Water of this scale does not typically fall out of a bright sunny sky. It is almost always associated with greatly decreased visibility --- sometimes even at night.

In the middle of such a downpour, most people aren't standing still like a dummy with their head, face and silhouette fully exposed to oncoming traffic.

Would the performance be better or worse in a more realistic scenario? I see no reason to expect anything but the latter. How much worse remains to be answered.

What this does show pretty clearly is the typical response when "triggered" --- slam on the brakes. There are reports of trash blowing across the road being a "trigger". Avoid following a Tesla if possible.