If, as you believe, this post was "assigned" points (which only HN staff can theoretically do), what do you believe you will achieve by flagging it?

All the points came from regular upvotes.

https://news.ycombinator.com/item?id=11271815 was indeed posted earlier. Unfortunately, youtu.be is banned because it is heavily favored by spammers. That's why that post didn't get seen.

We've assigned that video to the current submission (using the canonical youtube.com URL) since it was posted without a link.

Probably 20 people submitted same link in a short time.