Dear Queenie,
My boss is always nagging at one of my co-workers without reason. I would like to stand up for him, but I don’t want put my own (good!) relationship with my boss at risk.
Queenie, what should I do?—Worried co-worker
Dear Worried co-worker,
If your place of work has a Human Resources Department, this issue should be brought to their attention. If there is no HR Department, but your boss has a supervisor over him, perhaps that person could help resolve this issue. Other than that, there is not much you can do without, as you say, putting your own relationship with your boss at risk.
Basically, it is up to your co-worker to deal with his problem, if it bothers him as much as it bothers you. Is it possible there is a reason for this situation that you don’t know about, such as a personal relationship?