Your client calls you about a potential litigation situation. And the client is pleased to announce they’ve taken the proactive step of finding and talking to an expert witness. The client likes this expert. They want you, their attorney, to talk to the expert and use them for their case. Is there a real problem with this scenario? The client may have not considered confidentiality and potential negative discovery issues in taking this step. Namely, no privileged communications. The client discussed topics and facts discussed by the client not privileged and discoverable. And the information the expert witness now possesses is not privileged and discoverable as well.
Attorney-client privilege refers to a legal privilege that works to keep confidential communications between an attorney and his or her client secret.
This definition explains how communications between attorney and client are privileged from disclosure during discovery and trial phases of litigation. Communications between attorney and client are generally protected from disclosure in law. The ABA Comments Section 1.6 places communications between client and the attorney beyond disclosure.
The manner of use of an expert witness determines whether privilege is extended to the expert witness.
What about disclosures made to an expert witness? Well, it depends on who is involved in the communications. Communications between an attorney and expert fall under two basic levels of privilege: If the expert witness is retained/contacted to consult with the attorney but not issue a report to be used in litigation or to testify in deposition/trial then such expert’s work and communications and information obtained during his/her work is privileged.
Experts used to prep for trial, serving the attorney in a function in anticipation of trial but not be called to testify in trial is also protected. Experts work and communications with the attorney where the expert will testify in deposition or at trial are not protected by attorney-client privilege. It is presumed the attorney is cautious about what is communicated to the testifying expert with the understanding the same is not protected from disclosure. Clients may not be aware of this and hence not limit what is discussed directly with an expert witness.
So, to summarize, privilege attaches to all confidential communications between an attorney and the client regardless of whether the information communicated is in fact privileged. Privilege may be waived only by the holder of the privilege. The client is the holder of that privilege. When the client, the holder of privilege, communicates directly with the expert witness, privilege is typically deemed waived.
In the legal world, communications between attorney and client are protected from disclosure. Communications between the client and non-attorneys are not deemed privileged and hence not protected from disclosure. When a client communicates directly with an expert that communication is not protected from disclosure. Communications include all documents, drawings, internal company memorandums, photos, etc.
As you know, each state has its own specific interpretations of attorney-client privilege regarding expert witnesses. For example, some states protect prior drafts of expert’s opinions from disclosure while others do not.
Always check your jurisdictions interpretations of disclosure standards regarding expert witnesses to know the perimeters of disclosure rules regarding expert witnesses.
Greg Gerganoff, CSP, Esq., is a safety expert witness handling workplace injury/fatality matters involving oil and gas, mining, manufacturing, and construction. We help attorneys answer questions of a standard of care (OSHA/MSHA) involving workplace safety. My expert witness work is evenly divided between the plaintiff and defense. My safety experience covers approximately 19 years in mining, oil and gas, construction, and manufacturing. He is admitted to the Colorado Courts. email@example.com, Visit my web site for more detail at www.rkymtnsafety.com, or call (303) 330 4616.
 ABA Rule of Professional Responsibility, 1.6 Confidentiality of Information, Comment:
Client-Lawyer Relationship , 
 United States v. Korvel, 296 F.2d 918, 922 (2d Cir. 1961); Christine Funk, May 11, 2020, Expert Institute. https://www.expertinstitute.com/resources/insights/attorney-client-privilege-and-expert-witnesses/,
 Christine Funk, May 11, 2020, Expert Institute. https://www.expertinstitute.com/resources/insights/attorney-client-privilege-and-expert-witnesses/,
Court of Appeal, Fourth District, Division 3, California. (2016). P. 660
Court of Appeal, Fourth District, Division 3, California. (2016). P 669