Frankly, the more you know the history of the Orthodox Church, the more you would be inclined to say that they would never have executed witches. In fact great portions of the Eastern Orthodox Churches history, is when they have been the ones being executed, whether by pagans or heretics. In fact if someone told me that the Orthodox had executed witches, I would probably think that it was some heretical branch.
According to this link:
the Protestant reformers often agreed with Rome, that witches were a clear and present danger. All four of the major western Christian "churches" (Roman Catholic, Lutheran, Calvinist, Anglican) persecuted witches to some degree or another. (Eastern Christian, or Orthodox Churches carried out almost no witch hunting).
I would say that if the Orthodox Church ever found a "witch", they would have tried to purify him/her, and bring that person (back) to the Church. Also, no one was allowed to kill anyone, except as a soldier. Perhaps some corrupt Emperors would have done this, (In fact I know they did), but the Church Fathers would confront that emperor to his face and tell him he did wrong (though this is not an example with witches, I had to call to mind the story of Ambrose and Theodosius).
So if you have any doubts and questions, please tell me. I believe that the Eastern Church would never have done this, unless someone in authority was corrupted.
But then we are all sinners.