When a military general or Secretary of Defense asks if the 1960s missile warning system is working "correctly", it means it's working incorrectly when the moon is categorized as an incoming enemy attack.
Likewise, when a general asks if the 2018 warning system is working "correctly", it means the system is designed incorrectly if the pixels of text on the screen[1] lead operators to trigger the unintended action.
Categorizing one error as a "radar error" and another as a "UI error" as if they are 2 disconnected concepts of correctness is missing the point of BCS's essay.
When people think of something working "correctly", they want the whole system to work correctly. They will not explicitly enumerate all the subcomponents nor all the subdisciplines such as "UI design".