IMO, to handle the situation in this event only required training to be able to perform at the minimum standard of skill for being qualified to operate this aeroplane. This event did not require non-standard superior skills to resolve safely, just the correct proceedures! INU failure or Instrument comparitor warnings are not rare or "unforseeable" failures, I have experienced several, including one at night IMC after T/O as PF, and they will continue to happen.