Part of me admires their sober approach to safety, but another part is extremely skeptical of the implied reliance on mapping. Reality changes all the time, so

Part of me admires their sober approach to safety, but another part is extremely skeptical of the implied reliance on mapping. Reality changes all the time, so your technology should better be able to deal with outdated models. But if it can, shouldn't it be able to cope with an absent model just as well? If it does need a pre-made model of reality, I am not convinced of its ability to deal with unexpected change. In sports climbing terms (hope I use them correctly, not being one): how bad is the car at onsighting a road that it needs beta so desperately to flash it? Maybe their "onsight" capability is just very slow and the first Waymo to meet a change has to onsight it at hardly more than roomba speed (or worse: mturk?), sharing the knowledge ("beta") with the Waymos that come later, but then you still have to reliably detect that your model is outdated while driving regular speed while all false positives would considerably harm the relationship with other road users.