"Driving through a 4 way intersection, while a large truck is also going through the intersection. As you go through, a biker quickly passes behind the truck with minimal time to react once in sightlines."
A human driver would take significantly longer to react, and could be deadly.
Waymo managed to hit the breaks before the collision, potentially leading to only minor scrapes. Feels much better than human would fare in a similar scenario.
What I hope Waymo learbx for this, as well applies as similar scenarios: never cross through these zones of high bike traffic when the obstruction from another vehicle prevents a wide enough view to brake before this zone.