Crew O2 Bottle goes bang, takes out xpndr, comms and leaves a large hole in the fuselage
That's a very selected grouping of independent systems. 2 transponders, 2 HF radios, 3 VHF radios. Different locations, power supplies etc.
Incredibly the accident left enough nav gear serviceable as it seems to have navigated by way points that would not be in the initial flight plan so someone very likely put that into the FMS afterwards. If someone did that why not descend or land? Operate the completely independent ELT?