From an "insider" with over 40 years experience on commercial aircraft and 35 working on B747s, please note;- In that area of the fuselage on B747-400s between the right hand cargo lining and the fuselage there are 13 oxygen bottles, the first 7 of which are mounted vertically the remaining 6 are mounted horizontally. It appears that it is possible that one of the horizontal bottles may have let go and with 1750 psi projected itself through the fuselage skin and dislodged the fibreglass wing to body fairing.
Once part of the fibreglass fairing was breached the airflow would make sort work of the entire fairing assy. The location certainly aligns with the oxy cylinders and the damage is consistant with an event as described.