Take your point about the oxygen cylinders, but the smell was also mixed with cordite, but the masks only came down on one side of the aircraft, not all of them deployed either and even after pulling the mask, still nothing, possibly the system was damged in the explosion.
I think some serious safety questions need to be answered about airside security. Favori and SCAMA recently issued new flightline badges, they have made inroads and cut badge issues from around 3000 to around 1500, however people do come and go, without being checked, also, people are allowed to walk round the airport willy nilly, favori need to clamp down if running an airport is to be taken seriously.