Leaving a FATE early

[TurnBased]

Something I noticed as I've been FATE levelling...

I was levelling my SCH in Coerthas and we were fighting the Cyclops. At about half health, the Svara 3 FATE chain spawned. Suddenly, a mass number of people, including my party members began to teleport away as the boss' HP got lower(knowing that they had already gotten gold), leaving fewer people to kill the boss...

There were too few people(and no tank) left to finish the battle. People either died from the boss' AOE or just gave up and joined the zerg rush on Svara. We still got exp from failing, but I imagine we could have still gotten full exp AND beaten Svara if people weren't so greedy. It's annoying since this is one of the few FATE battles I enjoy since it's somewhat challenging. It also wasn't the first time I experienced this. There was a time when the Roc, Lightning FATE and Svara all spawned close to each other, with people abandoning the fight left and right. It was a disaster and that time, it was actually the Svara FATE that ended up unfinished.