We merged a comment into here from one of the gazillion previous posts of this thread; if anyone knows of any other good comments we can do the same for them.
It's because of HN's weird duplicate link policy. The way I understand it, When someone resubmits a link, and the second resubmission gets more traction than the original, then the comments/points of the resubmission are transferred to the original submission and the original submission's "timestamp" is set to the resubmission's timestamp. The modified timestamp is used in rank calculations (post rank decays based on age, so a newer timestamp means a lower decay penalty). The HN search site shows the true timestamp, which is why on this story you see a mismatch.
Another way to see this is by the looking at the post ID. The post before this one is 11445139 https://news.ycombinator.com/item?id=11445139 (posted 1 day ago), the post after this one is 11445141 https://news.ycombinator.com/item?id=11445141 (posted 1 day ago), but this post is 11445140 (posted 4 hours ago). By deduction, the original post was submitted 1 day ago sometime in-between the other two.
Basically the system gives credit to the original submission vs the resubmission. It does look like a bug, and I think it is quite confusing, IMO there should be a FAQ somewhere explaining how duplicates work.
https://hn.algolia.com/?query=How%20I%20got%20a%20game%20on%...
https://archive.is/ZJG4x
Not sure what could cause an older timestamp. Was this somehow flagged and readded or something?