When managers have a fear of confrontation, they often turn to manipulation for the solution.
The manipulation, in turn, can cause a loss of trust. Employees eventually catch on to the game and those who may of been in the know in the first place will wisely wonder, "If the boss plays games with my colleague, what is being done with me?"
The loss of trust, of course, is far worse than an unpleasant meeting.
Manipulators don't admit to their practices. They justify them by asserting that it is less disruptive to avoid confrontation, the employee would be unreasonable or there is no time to sort out the roots of the problem. What's worse is that sometimes the strategy works. There are moments when the clever deflection or avoidance of an issue does defuse a situation or matters resolve themselves. Occasionally, problems walk away.
The core danger of manipulation, however, is what it does to the manipulator. Bobbing and weaving can easily become a habit. Granted, managers who are as slippery as an eel may be otherwise competent.
You just won't want to turn your back on them.