You do raise a fair objection, but "black swan" events are a known issue where it comes to sampling.

For example, an answer to your question could be: "you asked us to find the average wing span to beak size ratio for male and female swans. Including the black swan doesn't change it at all, and the massively larger sample set doesn't improve our accuracy".

If you are doing things right you never say the equivalent of "they're all white" - you give a distribution. Explaining that and what it means is a communications issue, not a data one.

>"Then explain this black swan"

It's not black, it is a very dark white, and you might be looking at it with the wrong lighting.