I've played through the game twice and this happened both times.
Basically the fight starts and Zinyak flys upward and gets stuck on the ring of spikey things around the central platform. He stays there until his life gets depleted triggering the next phase of the fight. He does not fire while stuck in this way.
Basically the fight starts and Zinyak flys upward and gets stuck on the ring of spikey things around the central platform. He stays there until his life gets depleted triggering the next phase of the fight. He does not fire while stuck in this way.