It wasn't necessarily the manufacturers advice.
Yes it is the manufacturers advice.
The manufacturers advice, in terms of their QRH, and what the company did, in terms of THEIR QRH were two different things when this event happened.
Gosh Blah, I wish I had your outstanding airmanship qualities
My outstanding airmanship qualities were exactly the same as all the pilots at Air Nelson who also questioned why the Captain didn't take the hint from the FO and why they didn't take the time to have a think about the problem. The EGPWS going off should have been a hint.