Guild Wars 2

about 30 of us from my guild spend an hour waiting around on the Island did all of the events and then killed the boss, we all got gold for the event and opened the chest but only 2 or 3 of us out of the full group got credit for the achievement .

Very annoying for us after we spend so much time at it with the intention of getting the achievement more then anything else.

Can confirm. This is referring to the meta-event in Bloodtide Coast involving Taidha Covington aka The Hydra Queen.

Gold event completion was earned, and I was around for the full time to attack the boss.