A Hearing Committee may conduct a formal hearing in the presence of a quorum of two members. However, if a Hearing Committee member cannot be present, and that fact is known in advance of the hearing, an alternate member shall ordinarily be appointed pro hac vice by the Board to complete the Hearing Committee for the originally scheduled date. If during a formal hearing before a three-member Hearing Committee a committee member is unable to attend the entire hearing, the Hearing Committee may proceed with a quorum of two members or, upon the consent of the parties, the Hearing Committee member who is unable to attend the entire hearing may participate in the decision.