So why is it unreasonable to think that a computer can do this? This, being take a reasonable first reaction to a situation, namely stop, then follow up with a proper action once more data is available.

You don't stop though. You start to put your foot on the brake and then you take it off. Presumably, for a computer which doesn't really have different classes of reaction times in the same way, should never brake in the first place.

I don't think that presumption is true, it's a high bar that doesn't really provide much benefit to achieve. If a computer decides to tap the brakes because it thinks an "oh shit" scenario is coming up, why is that suddenly a huge transgression?

The point is that computers don't really have the same type of reflexes that humans have. The theory is that everything is pretty fast. (OK, they can run a background analysis in the cloud but that's presumably too slow to be useful.) Computers are generally not going to respond with "reflexes" and then change they're minds once they've had time to think about it for half a second.

Computers could possibly be designed with these sorts of decision making patterns if there were a need to but I'm not aware of that being done today.

> Computers are generally not going to respond with "reflexes" and then change they're minds once they've had time to think about it for half a second.

Well I disagree on this point, as that's essentially how regressions work, so indirectly how neural networks work. The data the car gets isn't available immediately, all that information it takes in in half a second is useful data that aids in classification and decision making.

Just as a quick example, take https://tenso.rs/demos/rock-paper-scissors/ and think of the classifier as "making a decision", and it switches its decision based on the most recent information.

The point is that all presumably happens "instantaneously" from a human perspective. Hence the claims that autonomous vehicles have no lag in responding to events.