Congratulations to Titan Ex designer
You have managed to design a very balanced fight. Undergear that #### and you'll get Sumo'ed to death. Overgear that #### and...
Geocrush happens with the healer still inside the gaol.
This actually happened to me two days ago. Our DPS were so strong Titan jumped with me still inside the gaol (second geocrush). You know that healers are usually the one at the border of the ring, and geocrush removed the ground under my feet. I fell with the gaol intact.
The correct countermeasure that we should have done would be to administer the dps carefully. But really, how are you going to do that?