Turin #2796
The fittings are on the rear/aft facing end of the bottle. If the fitting was to fail and the restraining straps were also to fail, then potentially, the bottle would go forwards not aft. That would send it either straight through the radome or potentially deflected upwards into the below flightdeck area. This contains the backdrive mechanisms for the control column and rudder pedals.
The possibility (of an O2 bottle failing as such) is remote at the extreme but not unprecedented.
I don't buy it.
What is the distance between the bottle's forward end and the bulkhead?
Accepting all your reservations I comment as follows.
If it hasn't built up max momentum it will not pierce the bulkhead, being round at the "front end" it will deflect and bounce around ( may even get stuck) but if it ever got to face aft this would propel it into the MEC, which by now is a fairly oxygen rich environment.
As an aside to those speculating the aircraft could have been "secretly" fully fueled you obviously don't know much about refueling procedure.
It is not like pulling up at the pumps needing 1/2 tank and deciding you might decide to go the scenic route and filling up instead.
At your hub ops will have informed refueling of the required load and that is all they will put in.
We once landed at an airport which was a regular stop and the refuelers knew pretty well how much we need to depart full and would send out a bowser and trailer. On this occasion we needed more, the driver would not let me have more, he asked to check the flight deck gauges, read the fuel content subtracted the input and stated we had landed below minimum reserve. I confirmed this and stated pilot was filing a report right then. I still had to fill in loads of paperwork for the fuel company.
YOU CANNOT JUST TOP UP