I have not yet had a good run at Ahune, and I've downed him only twice. Never on Heroic. Let's see what we have...
Too much melee dps, and most under-geared.
A moonkin who socketed blue gear with spell haste (for a total of +16 haste, woo!) and melee'd the rock elemental mob (the one with the stacking AoE debuff?) to get mana back.
A rogue who wanted the paladin to run back and rez him on a complete wipe so he could talk to a guildmate for a strategy, when we had already stated the strategy. And everyone else was running back.
A group just running in and summoning without clearing any of the packs of trash that roam through the area.
A group asking multiple times what the strategy was, while in combat, while I was trying to heal everyone and everything and get them to move away from the giant earth elemental mob and keep the trash off of me and stay out of the shiny ice (because it's totally cool to get shot in the air, guys!) and dps the boss when he's just a core.
At this point I don't think my luck will let me have a good Ahune run. I think he could be an amazingly fun boss. If my group is never at least 2/5ths full of stupid.