Complex sentence: Stubblefield, a proponent of facilitated communication, used the technique with D.J., whom she believed was of normal intelligence and, after in her opinion successfully communicating with him, brought him to conferences where she "held him out as a success story".
Split into simpler sentences: Stubblefield, a proponent of facilitated communication, used the technique with D.J., and stated that she had successfully communicated with him, determining he was of normal intelligence. She subsequently brought him to conferences where she "held him out as a success story".