That sounds plausible. Humans for the most part can usually navigate that situation to a point. It wouldn't surprise me if Waymo cars weren't even trained for this scenario.

The one time I saw traffic lights go down, it was total chaos. There were two separate crashes that had already happened when I got there, and there would probably be >1 wreck per few minutes with the driving I observed.

I moved from South Africa to Ireland 2 years ago. It was very noticeable to me how drivers in Ireland have no idea what to do when the lights are out. Absolute chaos!

In south africa, traffic lights not working is a daily occurrence. And we've all learned how to navigate a dead intersection wit zero casualties.

Massive 6 way intersections with 2-4 lanes per direction worked perfectly with everyone taking turns to go.

I lived in the training zone for both Waymo and Cruise. They were there for literally years before they were offering rides to anyone. The idea that they could train them for emergency scenarios, especially ones that happen so infrequently like a power outage on a route they regularly drive, seems borderline nonsensical, but I honestly don't know if there is a plausible way to do it.