The safety investigation board revealed...
The copilot who was not flying said he felt uncomfortable with what he saw, but assumed that the Captain knew what he was doing, so he said nothing...
Meanwhile, the Captain didn't realize that he had forgotten to call for that particular item, and would have responded to a prompt from the copilot...
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When you brief an approach, you set the expectations for the entire crew, and you build a baseline from which to compare your actions. You build confidence in the other crewmember(s) and allow them to back you up along your intended course of action. The moment you deviate from what you brief, whether intentional or not, they can query you as to your actions. Either you changed your mind, or they saved you from messing up.
There is usually more than one than one way to skin a cat - - fly the arrival, fly the approach, configure the airplane, descend to MDA, etc. Tell the other guy what your plan is, and he's part of the team. Keep it to yourself, and he's just an observer making radio calls.