[jchung]

> 100% not at fault When something significant goes wrong, it’s almost never due to a single cause; multiple factors and confounding elements are usually at play. We build better-performing systems when we examine various contributing factors and proximal causes.

The OP's argument is that the interface does not "clearly" indicate that one engine input is higher than the other. After reading the article and reviewing the interfaces, I have to say: the OP’s argument is quite compelling. While training is undoubtedly important and should be included in the safety recommendations, the OP makes a strong case that design improvements should also be considered as part of the safety recommendations.