Do not casting Lighting Ball, so Hunters do not able to Tank this boss. So HKM fight become much more difficult.
furthermore very diffucult pull these Bosses because moveing very very fast.(the pull the most important part of the fight)
This is hardly a major priority, a major priority would be something that has the possibility to crash the realm and/or is totally broken. Getting bosses to work like they do blizzlike is a minor priority.
You mean Spell: Lightning Bolt? since I can't find any reference about this Lightning Ball. To top it, how can it not cast it? it's scripted so he does use this spell.
Maybe the spell is bugged or has no visual effect, its scripted, thats true but sometimes spells are not working