I'm not sure if this is a repost.
This is found by me and my guild, and I've not read about this exploit before.
On the thrash to Akil'Zon you need to keep the raid in combat.
By pulling a pack then when the last mob is on like 30% (Doesn't really matter just pull before the last mob is dead) pull the next pack. And just keep this to the boss.
However the birds for the first pack will spawn.