Audience with the king bug

I bought an audience with the king from the currency exchange, and went into the instance with 2 friends. Once we got the king down to 25% health, he went untargetable, and we had to navigate the maze. Once we left the maze, he was stuck in an untargetable phase, and never progressed. I lost out on the Divine Orbs, as well as all the time I spent waiting for the fight to continue. What can be done about this?