Like most AoEs in this game, damage is triggered based on where your character is standing when the cast bar/ability triggers (Not when the visual que trggers). Take the last boss in keep for instance - you can run out and reengage the boss the moment the large AoE cast bar ends and be perfectly fine. Even though the graphics for the ability are still active, the character hit/miss check has already triggered. Best solution on Titan, move faster.

Not trying to be rude here, but there is plenty of time to get out of the AoEs, the fight is VERY well tuned. Just because people decide to play on non-local server doesn't mean content should be nerfed for the rest of us.