The flag is obnoxious (duplicates and okay-but-inferior sources don’t seem to violate the guidelines, and flags are about guideline violations), but ChrisArchitect is right: this link seems to be the same content but much more informative:

https://news.ycombinator.com/item?id=40584135

And that post is alive and well and not flagged.

>And that post is alive and well and not flagged

Because dang turned flags off for that post:

https://news.ycombinator.com/item?id=40586937

https://news.ycombinator.com/item?id=40586961