FB41
Been to JNB many times myself over the years in BA latterly as P1 on the B744.
I think it is clear to everyone that the flight crew (backstop the captain) on the day were ultimately resposible.
However, given that they didn't intend to taxi into the building, what will benefit pilots, companies, airport authorities, and regulators around the world will not be the fact that the crew took the wrong route that night, but what the contributary factors were.
They could include, but not be limited to :
company induced distractions (loadsheet mesages)
poor briefing techniques possibly resulting from
poor material quality/detail from chart providers
non standard/inadequate airfield signage,
poor taxiway lighting
non-optimal atc monitoring/equipment,
[add others factors as required]
Very few things in aviation are black and white, I doubt that this incident is either. Best let the appropriate authorities (hopefully with a substantial UK AAIB role in it*) report before throwing pilots to the wolves.
(*) UK AAIB as we all desire a report that is impartial and factual, and they have a worldwide reputation for doing just that