Don't ya just love those who come up with these own facts and state them as such without understanding what they are doing. I'm guess the problem they had with the cell was a loss of contact between the plates and one of the terminals and jumped to the conclusion the battery was fully discharged.
When he spears the case, vapour pours out due to a short between fully charged plates, the red glow inside showed clearly the plates where still holding quite a bit of capacity and were shorting across each other. The second stab he creates a short between the aluminium case and the charged plates inside, this creates a spark and ignites the hot vapour.
If the cell really could produce all the elements required for a fire, fuel, oxygen and ignition, then the flame wouldn't be red/yellow, it would be blue and very fierce in deed, the swelling probably would have occurred and the cell actually explode because the pressure build up from the internal fire wouldn't be able to vent through the holes provided.
The take away from this, don't drive a sharp metal object repeatly through om aluminium cased cell
I think Boieng already conducted a similar test where a brainless technician wound a bolt far too long for the space available, using a power tool so no resistance was detected, and screwed the bolt right though a cell ...... this was not an LFP cell the Boeing technician shorted out but rather a lithium cobalt manganese chemistry cell, so the fire was much more dramatic and lead to thermal run away .... much like these Tesla cells
https://www.youtube.com/watch?v=WdDi1haA71Q that is the sort of fire you get with other chemistry lithium cells being installed and charged by people who don't have a clue what they are doing .....
T1 Terry
T1 Terry