Last I heard there were two theories on why the bottle blew, one was that the bottle may have been dropped prior to fitting and the other was that the bottle had some water in it and it corroded very quickly due to the high O2 level in the bottle.
As there are no pieces of the bottle left it's hard to tell what really made it blow and we may never know.
As for blaming foreign MROs this was all in house work right back to the D check done in Sydney, sad to say.
The lap join AD is not relevant to this incident but it has to be said that Boeing's engineering stood up extremely well yet again.
Qantas was very lucky again, but I can't help wondering when that luck will run out.
