I posted something similar elsewhere as a comment, but I think it bears repeating.
Bishop Duncan was not inhibited, but it appears as though the Presiding Bishop is moving ahead to have him deposed. The time line stated in her letter to him makes it clear that the Fall meeting of the House of Bishops will be the critical one.
The problem is that the sole arbiter of the fairness of any proceeding before the House of Bishops is the House of Bishops. There won't be a lot of due process here.
My take on it is that Bishop Duncan will be deposed in the Fall, if he is still around. I'll bet dollars to doughnuts that the Diocese of Pittsburgh will have withdrawn from the Episcopal Church by then.
I think that is what the Presiding Bishop is counting on. Things run much more smoothly in a trial if the accused is not present. Internally, I think this is what she sees.
As far as the greater Anglican Communion, I doubt she will win any friends by what she is doing. She may very well alienate some, who under other circumstances, would be her supporters. I doubt that concerns her much.
While the church documents may charge Bishop Duncan with abandonment of the communion of the church, this whole debacle shows that the Presiding Bishop has abandoned the Anglican Communion.