Ok let me try to understand what you are saying, so contact between lithium and water would cause an explosion with the release of hydrogen, the batteries contain lithium thus the batteries would have had to been either exposed or gathered steam from a shower?Build is irrelevant, he took hybrid mech to the bathroom " getting ready for work". Mod gets wet he pulls a drag and shorts it out. Lithium in presenece of water release hydrogen and more heat. Explosion of that magnitude could have been caused only by hydrogen ignition.
In short, man is a moron.