> It's very hard to imagine a scenario in which a 49-year-old woman walking her bike manages to cross 3 lanes of traffic so quickly that the Uber AV, moving at 40 mph, had no time to react, in a location with good street lighting and with clear weather

Explaining the imagining, is the salient issue.

> The parent didn't say that he is imagining anything

Splitting hairs over the phrasing is not compelling. The poster was proposing a scenario as the most reasonable interpretation while couching it to minimize criticism (the equivalent of the "just sayin" trope).

The premise is flawed. It never sounded reasonable to assume the pedestrian did not see the vehicle at all. I can imagine a perfectly reasonable scenario where the pedestrian tried (and failed) to clear the vehicular path before being struck on the attempted destination side of the road.