I would certainly have more faith in a good automated QNH system (or a forecast or my PIDOOMA) than one run by an untrained observer. Whether or not CASA had given its seal of approval.
Several years ago a B737 crew had a lucky escape on approach at Honiara. It was summer and for some reason they understood the QNH to be an impossibly high value for that time of year. They read it back to the controller, and set on their altimeters, something like 1024 when the QNH was more like 1004.
Lucky for them they got visual early enough to avoid the ground, because with the aircraft in landing configuration the EGPWS was not going to save them.
Even allowing for some language difficulty or possible controller finger trouble, that crew demonstrated a woeful lack of understanding of tropical meteorology.