I'm not the same person you were responding to earlier? You seem rather emotionally wound up in all of this. Someone doesn't need "evidence" to say "I noticed A". The evidence is right there - they're claiming to have seen it.

Among other things, you've put yourself in the position of claiming - but not arguing, because you provide no reasoning to engage with - that there are no black swans in the world. It's entirely untenable.

What they saw might have been an outlier. Perhaps they misunderstood. They might be confused or uniformed or any number of things. They could even be lying outright! But to respond by dismissing a claimed observation without evidence or reason is not a constructive attitude and I would even argue anti-intellectual.