> The most ambiguous case occurred in Phoenix in May, when a cat crossed a street ahead of a Waymo. The Waymo braked, but couldn’t avoid hitting the cat, “which subsequently ran away.” The sudden braking caused several cars to rear-end the Waymo and each other.

That's not ambiguous at all. If you are unable to stop in time if the car in front of you slams on the brakes, you were following too closely, and that is your fault.

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RivieraKid 20 hours ago | parent [-]

But there was no car in front of the Waymo, it was a cat.

	▲	B-Con 20 hours ago \| parent [-]
		The cars behind the waymo and hit it were at fault for the collision. My guess is that the ambiguity is about the trade-off: "even if no one should hit you for slamming on the brakes, is it a good risk to take over a cat?"