回复：如果老板想把同事report给你，但不是你升，而是同事要被demote

Demotion is a bitter pill to swallow, your colleague has much harder feeling than your headache. 

Just thinking out of box, how about 1) finding leadership training opportunities for her/him; 2) trying assign some your direct reports to her/him?

The benefits are 1) his/her success is your success, 2) letting him/her to lead some your folks makes her/him feel better while growing your dept.