My understanding is that Bishop Ackerman asked the presiding bishop not to undertake this action at this time because of Bishop MacBurney's family situation. From VirtueOnline:
Mrs. Katharine Jefferts Schori, Presiding Bishop of the Episcopal Church, has formally inhibited The Rt. Rev. Edward H. MacBurney, retired Bishop of Quincy. Two days after the letter of inhibition was signed by the Presiding Bishop, MacBurney's son Page died.
Bishop Keith L. Ackerman SSC, Bishop of Quincy, said MacBurney was not aware of the inhibition. Ackerman had to read the inhibition to him over the phone.
"I am beside myself with grief over this unnecessary action taken against my predecessor especially at a time when he is mourning the death of his son this past Friday. I am particularly saddened that, with the exception of the Bishop who initiated this action, those involved in determining this course have never spoken with Bishop MacBurney directly. In the midst of this difficult time for Bishop MacBurney and his family, I am really much more concerned about the implications of St. Matthew 18:15-17 as it relates to how reconciliation is pursued than I am with Title IV, Canon 1, Section 6 as it relates to discipling my dear brother. In the meantime, we are ministering to the needs of the MacBurney family."
Mrs. Jefferts Schori said the presentment issued by the Title IV Review Committee was based on Title IV, canon 3, Section 43Copyright, 44, and 45 of The Episcopal Church. Bishop MacBurney is inhibited from exercising his gifts of ministry and will face a court trial.
Read it all. And the bishop who initiated this is San Diego's Bishop Mathes.
H/t to MCJ.