Just flag it, scan through the poster's other submissions/comments and flag all similarly rule breaking posts, and move on.
Here are links to many posts throughout the years posted by others with similar content that weren't flagged and that generated a tremendous amount of conversation with many insights to be had from reading them:
https://news.ycombinator.com/item?id=16996420
https://news.ycombinator.com/item?id=18613124
https://news.ycombinator.com/item?id=42070946
https://news.ycombinator.com/item?id=42396733