I'm not really sure if this is an exploit or if everybody will say it's an easy fight and this doesn't matter.
When one of the ice spikes forms, stand where it will throw you in the direction of the raised terrain, opposite the water. If you were close enough, you'll land on the higher ground.
From there, I was able to blast Ahune without having to worry about the adds coming after me. This is worthless for melee, but makes things even easier for a caster.
Sure, the tank should be intelligent enough to grab adds off the healer, but I'm sure I'm not the only one that's gotten terrible groups.