They may also be experiencing stress or even lack of sleep which can affect their ability to think, and more importantly to act objectively.
The important thing for leaders to recognize is how they interpret information and then what behaviors do they exhibit when faced with a situation where they need to be objective.
Past experiences, upbringing, culture issues, gender, etc. all can affect a leader's thought process, especially when faced with a situation that he or she may not even want to deal with.