Blackwing lair first boss glitched!

Basically, i got a small raid group together to do blackwing lair and the first boss is glitched, everything seems like its going fine until half the eggs have been cracked then the boss randomly disapears and when you touch the orb nothing happens however the mobs keep coming, both gates are locked so no one can leave and the only way out is to wipe :s

please give any information possible