Yes that was a five year old HN post so it was the crop of SO clones from 5 years ago. They constantly change.

Example from now:

https://coderedirect.com/questions/190779/changing-the-color...

They even have the same url fornat and everything.

Actual result

https://stackoverflow.com/questions/11862315/changing-the-co...

Here I took a random SO post and searched for a sentence in an answer. This result is in the top 5 results (in this case the real SO result was above - but not rarely the impostor sites are above)