[mabbo]

The point remains: it isn't fair to decide what the probability is with only one data point on one side- especially for rare events.

Would it have been fair if Uber last week were to declare that they have a 0% probability of pedestrian deaths, since they'd never had one yet?

The goal of these statistics is to predict future outcomes. But with such a small data sample, you cannot fairly predict the future- just as in my lottery example.

[ggg9990]

What if Uber’s first self-driving car killed a cyclist in its very first mile of operation? Would you find it equally hard to draw conclusions?

[soyiuz]

It would be fair to approximate it was near zero per however number of miles they drove, just as it is fair to approximate it is one per three million miles today. Think of it the other way, we know with a high degree of certainty the fatalities are not one per mile, for example.