This report is only about the initial blow out. The failure of the BOP's to seal it off once it happened is another matter. And as to the rig itself I really don't think it would reveal anything about the incident. The gas came up the riser pipe and something ignited it. No doubts on that. As to the ballast tanks, there are lines in and out to add or release water as needed to stabilize the rig. I'm sure with the explosion and the fire valves could have been opened that flooded them or even ruptured the tanks allowing seawater in.