By Tara Hoke
This column reports on a court case involving an engineer’s conduct as an expert witness and highlights a potential area of tension between the goals served by professional codes of ethics and the policies guiding the U.S. civil court system.
Situation
A residential homeowner discovers cracks in his home’s foundation and other signs of subsidence, damage that the homeowner attributes to excavation occurring on his neighbor’s property. The neighbor offers a plan to address the damage, and the homeowner contracts with a local engineer to review the neighbor’s proposal and to provide guidance as the homeowner works to reach agreement with his neighbor on the necessary remedy.
Unfortunately, discussions between the homeowner and his neighbor prove unfruitful, and the two parties proceed to litigation; the engineer is hired to serve as the homeowner’s expert witness. At trial, the engineer testifies on behalf of his client as to the cause of the damage and the expected cost for the homeowner to restore his property.
The homeowner’s suit is ultimately successful, and he is awarded judgment for the repair costs as identified by his expert witness. With this sum in hand, the homeowner looks to hire a contractor to repair the damage to his home and to restore lateral support to his property. But to his surprise, the quotes he obtains are more than double the amount identified by his expert as the cost for the work. The homeowner contacts his former expert witness for assistance, but the engineer is unable to provide names of any contractors he contacted when calculating his estimates, nor any other basis for his testimony regarding the expected costs of repair.
Incensed, the homeowner files suit against the engineer, arguing that the engineer was negligent in determining the estimated cost to repair his home and property and that this negligence denied the homeowner the opportunity to seek restitution for the true cost of the work.
The litigation tests a gray area of the state’s law, with one party arguing that the engineer should be judged by the professional standard of care, while the other points to the widely practiced legal principle of granting immunity from civil liability to trial witnesses, a principle designed to promote candor in witness testimony without fear of retaliatory lawsuits.
The trial court rules in favor of the engineer, but an appellate court reverses the decision and holds the engineer liable for negligence. On appeal to the state supreme court, the court overturns the prior decision yet again. The court opines that, even if the engineer were negligent in preparing to give an expert opinion at trial, the only action that caused harm to the plaintiff was the engineer’s testimony itself — and for that reason, the principle of immunity for witness testimony still applied.
Question
If the engineer in this case were an ASCE member, would his actions be considered a violation of ASCE’s Code of Ethics?
Discussion
This case went to trial during the 1980s, at a time when Canon 3(c) of the ASCE Code of Ethics read: “Engineers, when serving as expert witnesses, shall express an engineering opinion only when it is founded upon adequate knowledge of the facts, upon a background of technical competence, and upon honest conviction.” This same principle is embodied in today’s code in section 1c, which instructs engineers to “express professional opinions truthfully and only when founded on adequate knowledge and honest conviction.”
If this case involved an ASCE member, it is likely that ASCE’s Committee on Professional Conduct would examine whether the engineer possessed “adequate knowledge” to testify about the costs of remediating the homeowner’s property. If the engineer could identify a reasonable basis for his testimony, the CPC would be unlikely to find fault in his conduct even if his calculations were incorrect. However, if the CPC believed the engineer had held himself out as offering an expert opinion when his estimates were mere guesswork, or made without sufficient rigor or verification, the CPC would probably conclude that the engineer had violated his ethical obligation to express professional opinions “only when founded on adequate knowledge.”
The difference between this ethical analysis and the court’s ultimate ruling might suggest that ethics and the law take conflicting views of the conduct in this case. And indeed, though ethics and the law often go hand in hand, the two measures serve different purposes — with ethics operating as a framework for moral judgments, while the law aims to create social order and protect individual rights. Given this disparity, it is not surprising that ethics and law can sometimes reach different results. An engineer’s mistake or error might be grounds for legal liability but not reflect the degree of moral culpability necessary to deem the conduct unethical. Conversely, an act of deceit or manipulation might be considered highly immoral without breaching any legal obligation.
In this case, however, it is more accurate to say that the ethical and legal principles under consideration reflect a desire to reach the same result, but with a stark difference in approach. In reaching its verdict, the state supreme court expressed concern that the threat of liability from dissatisfied clients might “encourage experts to assert the most extreme position favorable to the(ir) party” and cause them to “function as advocates rather than impartial guides,” according to the court’s decision. Given the importance of expert witnesses to the judicial process, the court felt that civil immunity was necessary to protect the integrity of expert witnesses.
Likewise, section 1c of today’s code also reflects an attempt to protect the integrity of engineering opinions. Because of the importance of engineering expertise to courts, clients, regulators, and the public at large, the ethical mandates of knowledge and conviction reflect the profession’s collective intent to hold its members accountable for failure to meet appropriate standards in forming and expressing their engineering judgment.
While the supreme court in this state came down firmly on the side of immunity, it is worth noting that not all states are in alignment on this issue. Courts in numerous other states have scaled back on the presumption of immunity as applied to expert witnesses, finding that the objectives of the court are advanced and not hindered by applying appropriate standards of care.
Even in the absence of legal liability, a decision to cut corners or to offer misleading opinions is never without consequences. As expressed in ASCE’s Guidelines for Forensic Engineering Practice, authored by what is today the Forensics Engineering Division:
Shoddy work, lax procedures and questionable practices can result in reduced credibility of the expert witness system, and increased challenges to the veracity (and) importance of forensic engineering practice.
Both as a matter of professional reputation and respect, and to protect the integrity of the engineering profession, engineers should always be mindful of their ethical duty to be truthful, objective, and rigorous when providing a professional opinion.
Tara Hoke is ASCE’s general counsel and a contributing editor to Civil Engineering.
This article first appeared in the March/April 2026 issue of Civil Engineering as “Expert Guestimony.”
