If the gas used all/most oxygen, it would simply extinguish itself. Gas does not linger much on surfaces, and like I tried to show you with the gas from the lighter, even 1300 Celsius does not burn the skin if the explosion is short lived.
Had it been napalm in the container, and it stuck to the mop suit, I guess it could burn through the flame retardant kevlar in a few phases. A gas explosion would hardly even burn through a pair of regular pants and a shirt.
http://www.youtube.com/watch?v=BLAEmNLQHI
Not really a good example, but shows how gas is consumed.
http://www.youtube.com/watch?v=rFMYqPIE9mc
Shows lingering gas due to cold. Still don't think it would burn through the kevlar in one phase.