Somebody reached our blog by searching the following phrase in Google: "Can you be innocent of breach of fiduciary duty, but guilty of breach of the duty of loyalty?" The answer is quite simple, NO! The duty of loyalty is a fiduciary duty.
The more interesting question is whether you can breach your duty of loyalty without breaching your duty of care, which is what the person performing the search may have intended to ask? Clearly one board member can breach her duty of loyalty if the other board members don't act with care to prevent or stop such breach, but the two breaches involve different people. Well, we are probably "in angels dancing on the head of a pin" territory when we start asking these questions.