I'm not sure that moral responsibility for investigating the legality of instructions should rest with the employee, in cases where the instructions aren't clea

I'm not sure that moral responsibility for investigating the legality of instructions should rest with the employee, in cases where the instructions aren't clearly repugnant. Consider the example of engineers getting the details of tax compliance in a payroll system wrong because their boss provided the wrong instructions. To my mind, they should not be at fault for this unless they demonstrably knew what they had been asked to do was illegal.