...the cause of the crash was a bomb bay fire...
Wasn't that actually a cocked-up RAT/AAPP drill? Drop the RAT, volts and frequencies out of limits, but hey, connect it to the synch busbar anyway. Then impossible to disconnect from the aircraft AC system, cue fire, brimstone and shortly afterwards, one less Vulcan...
After which came the RAT field switch mod, which would kill the RAT in such circumstances if it over-volted.