Lawyers are often given instructions by clients that they have in fact been involved in a death, but that it was accidental, they panicked and then hid the body. In such a scenario the lawyer is ethically barred from revealing to police or relatives that the missing person is in fact dead. Sometimes the lawyer will even be told by the client where the body is. Keeping that knowledge confidential can take a real toll. If the client does not want to make any admissions then the lawyer must act according to those instructions.
This surprises me, but I sense from your previous posts you,know your legal stuff! I simply cannot believe a lawyer could act in the knowledge that a client has provided them contrary advice to what they may be prepared to testify.