Why not public hearings into the Wright-Duffy affair?

The House ethics committee is scheduled this afternoon to consider Scott Andrews’ motion that a study of Nigel Wright’s payment to Mike Duffy be conducted. Kady O’Malley has the full text of the proposal.

With apparently even the Prime Minister and his office unsure of precisely what occurred and with the Prime Minister claiming to be quite angry about it all, surely this would seem to be a fine opportunity to begin sorting out the details of this odd affair in an open and transparent manner. Put another way, is there any good reason Conservative members of the ethics committee could vote against such a study?