PickyPerkins:
Did they try a short-circuit on the battery?
Wouldn't that release all the stored energy in short order?
I believe that they tried an external short circuit of one cell, and I know they tried an internal short circuit (nail) of one cell.
I think that in both cases the cells were not in closed battery case with other cells when they tried it. It has also been observed since then that because of contact area, contact resistance, and electrode resistance problems a nail may not actually be a worst case internal short. It also immediately vents the cell!
A short circuit of the entire battery might not be a worst case either compared to thermal runaway. To get 900 amps from the battery, you have to use something close to a short circuit anyway.