> could just be, and seems to be in some cases at least, because Waymo doesn't behave like a human would, and people gets tripped up

Driving conventions vary wildly across states and even within them. And foreign drivers are a thing. A human who gets tripped up by a Waymo acting unusually will also get confused by someone getting used to no turns on right in Manhattan, driving on the right side of the road if coming in from the Commonwealth or adapting from California's protected left turners can turn into any lane, not just the leftmost. They'll also get confused by children and pets, who aren't bound by social custom, and deer, who aren't bound by physics.