O2 is highly flammable! If you have a O2 leak almost anything can ignite it including any petrol product source without a open flame or spark. Remember the Apollo astronaughts killed in the O2 fire in training. A O2 leak in the EE compartment on a Delta 727 destroyed that aircraft at the gate in less then 3 minutes. The Navy which uses 100% O2 in fighters forbids using any petrol products on the face to avoid fires. In this case it clearly was not a fire but a failure of the bottle however stating O2 is not flammable is very wrong.