I will consider it as sabotaging since someone definitely competitive enough to block my ShowHN post. That's why moderators are needed and tooling for moderators.
Regardless, reading as if it were "advertising" would possibly trigger the anti-advertising users, and HN is likely to have a slightly higher percentage of "anti-advertising" users than found in the general public. They may never notice the "ShowHN" label once they are triggered to think "just another SPAM".
There's only two ways to get flagged: automatically via defence mechanisms, or submitting something HN users deem inappropriate.
There already are moderators and mechanisms for HN users to "vouch" for flagged posts too, your post doesn't seem to be flagged now so I guess some people did that.
