Whenever the Dalai Lama refers to a Protector, it had always been Nechung. Nechung although unenlightened seem to be revered and trusted by DL.
It was also Nechung who requested the promise of Dultzin to be the new Dharmapala. So can it be that Nechung is evil. Not at all but maybe Nechung is on verge of enlightenment and his work as a Dharma protector may end and the New Dharma Protector's time has arrived. Obviously it being Dorje Shugden.