Guild Wars 2

reporting exploitation on turnament map :
send to exploits@arena.net

I think you’re supposed to report that to ANet directly instead of revealing that to public.

I thought it was better to show that they knew precisely what and how?
it is not a useful exploit in paid Turnament

You will not exploit any bug in Guild Wars 2 and you will not communicate the existence of any such exploitable bug (bugs that grant the user unnatural or unintended benefits) either directly or through public posting, to any other user of Guild Wars 2.

From the Rules of Conduct.

Exploits should be reported via email to exploits@arena.net