This one was hidden by the forum's automated spam detection system.
It seems to work like this:
- Forum member publishes a post and it becomes visible to everyone.
- The post is submitted by the forum software to the "Akismet" spam detection service.
- Akismet reports back that the post looks like spam.
- The forum software hides the post from public view.
- The forum software submits a flag for the moderators to review the automated action.
- The moderators see it was a false positive and reject the flag.
- The forum software restores the post to public visibility.
So there is this somewhat odd situation where the post is visible for a short time before seeming to disappear for the non-staff users who can't see it.