The event “Defend Klement and Fabri from pirate thieves” which follows “Collect dwarven artifacts from False Lake for Innkeeper Klement” has been failing while the pirates strength is around 50%. This has happened twice to me, once just now and once ~16 hours ago. In both cases, there have been several players helping and we have been killing the pirates in a timely manner. Once the pirates strength dips below 50%, the event “Defeat the transformed pirates” begins, which, according to the wiki, is the event triggered upon failure.
This is personally frustrating because I need to kill Lord Ignius, who spawns at the end of this event chain, to unlock a trait. This mesmer doesn’t want to pay for traits!