I’ve been trying to figure out how the tank imploded and can only surmise that they draining the tank ( pumping the contents out) at a high rate of discharge and the vent on top somehow closed creating such a vacuum as to cause the sides to collapse inward and splitting the tank open. The sudden release of vacuum pressure them caused the material to backflush and spray outward.
Just a WAG.
Your hypothesis makes perfect sense to me. I can’t imagine how else a tank full of liquid could implode.