Dr. Kenneth W. Davis writes about improving communication skills and recently commented on a blogpost I wrote on how to deal with an angry student's email. He states that the advice to wait before replying applies to dealing with colleagues and superiors also. He shares that a former dean advised him:
"As a department chair you don't have to reply to a disgruntled faculty member immediately, either face-to-face or by e-mail. You can always say, 'I'll think about that and let you know.' It's one of the few real powers you have."
As Ken notes, that was one of the most useful pieces of advice he has ever received.
Obviously, this applies to dealing with superiors or subordinates, administrators or students. You can't control what others do but you do get to choose how to respond. Waiting to reply gives both you and the other person time to think through the situation in a more rational manner.