HN is not a "whatever isn't explicitly prohibited is allowed" system. Instead it flows from general principles, and one of those principles appears to be that if you're caught abusing the system, there might be negative consequences because abusing the system is detrimental to its integrity and probably creates more work for somebody.
- We have a system in place that prevents duplicates.
- Except we expect you to find holes in it and bypass it when necessary.
- Except you should never delete the original before posting a duplicate.
One would think the existence of a dupe detector implied a rule against duplicates, much like a low fence still implies private property.
Good referees make the calls that need to be made at this time, in this game, with these players. They have discretion. Compare that to basketball where all fouls must be called even when calling the foul clearly rewards the team committing the foul and gaining that reward was the explicit reason for fouling.
The reason futbol can be officiated differently from basketball is because futbol has Laws and basketball has rules. The futbol referee doesn't judge events solely by the book, but also by their effect on the Spirit of the Game.
The duplicate post heuristic exists to prevent problems and maintain the general enjoyment of HN. It's not there to encourage lawyering up and arguing a case, because that's nothing but a headache.
If this is seriously likely to affect you, act on the side of caution. Act as if the rules were explicit and restrictive and the punishments severe. In other words don't try to get away with something, and if you do, don't complain if something unpleasant results.
As Thomas Hobbes theorized, the sovereign's sole responsibility is to do whatever is necessary to keep the peace and we cede some of our autonomy for the sake of that peace. It ain't a democracy.
[BTW: user 'dang' is the HN moderator]
I get that that's frustrating to anyone who would prefer a precise spec, but don't forget that there is at least some compensation for the lack of an exhaustive rule book: you can get answers to questions by asking us. Please send questions to email@example.com.