Check the post from a new account, with "show dead" enabled in the options. Likely it was auto classified as spam. Quite a few people browse with show dead, so it's possible someone will vouch for your link and un-dead it.
To HN Mods, I suggest instead of just auto classifying it as spam. Maybe add a warning to that submission that it was classified as spam and if the user still wants to post it considering it is mark as spam, then it's upto them? Thank you.
If you want to check if this is what happened - yes. I'm giving you a workaround to check, not advertising a workflow.
> Maybe add a warning to that submission that it was classified as spam
I don't expect they'd go for that... Marking things as spam is useful for the readers. For the writer it just mean, "keep rewriting the data to find out how our filters work and how to bypass them".