> No one said that it's not possible for a pedestrian to be at fault in a collision; they said the opposite.

The intention of the comment you accused of replying to a straw man was meant to point out that a pedestrian could be at fault instead of the driver.

That reply is pretty clearly arguing that even if the pedestrian was at fault, the driver would still have to be at fault anyway. Summarizing an argument after quoting it isn't misquoting it.

> A pedestrian could be at fault in other scenarios, like running into the middle of the street in dark clothing at night.

There is nothing to distinguish this from the original argument where the driver could still be be accused of "driving faster than conditions warranted" because visibility is lower at night.

> In California, if a pedestrian is in a crosswalk then the driver is legally at fault

And strict liability rules like that often lead to ridiculous outcomes, e.g. if someone jumps out of the back of a truck into an intersection and you then hit them, technically they were a pedestrian in a crosswalk. Or there is a pedestrian standing next to a crosswalk but they're stationary and talking on their phone without seeming to want to enter the crosswalk, so you start to proceed and then they step in front of your car.