Managers can often spot bad decision making in others, but they may fail in identifying their own poor decisions. psychologists refer to this as:

The answer is bias blind spot. It is the cognitive bias of knowing the impact of biases on the judgement of others, while failing to see the influence of biases on one's own judgment. The term was formed by Emily Pronin, a social psychologist from Princeton University's Department of Psychology, with colleagues Daniel Lin and Lee Ross. Most people seem to display the bias blind spot. In a research, a sample of more than 600 residents of the United States, more than 85% believed they were less biased than the average American. Only one partaker believed that he or she was more biased than the average American. People do differ with regard to the extent to which they exhibit the bias blind spot. It appears to be a steady individual difference that is quantifiable.