Mike - thanks for that. The report makes it clear that the inbound Korean crew had done a very good job in analysing the fault and clearly debriefing it; unfortunately the maintenance team had basically focused on the instrument output rather than the faulty input.
That said, the pre-existing failure should not have caused a fatal accident; notwithstanding the ADI 'failure', prompt, correct action would have saved the aeroplane, its crew and cargo.
In my view the root cause could possibly have been too rigid an adherance to the 'If everyone's happy, shall we run the checklist?' culture at a stage of flight when correct, instinctive and well-practised actions were essential.