ok, let see what the definition said:
Vmca : Air Minimum Control Speed is the minimum flight speed at which the airplane is directionally controllable as determined in accordance with FARs. The airplane certification conditions include one engine becoming inoperative and windmilling, a 5-degree bank towards the operative engine, take-off power on the operative engine, landing gear up, flaps in take-off position, and most rearward C.G. For some conditions of weight and altitude, stall can be encountered at speeds above Vmca as established by the certification procedure described above, in which event stall speed must be regarded as the limit of effective directional control.
extract from BE76 Airplane Flight Manual
So based on this definition everything can be clarified... and updated to general definition ...
I hope its help you.
bye
Bruno