The Multifaceted Expert Witness: Serving Both Plaintiffs and Defendants

By Noah Bolmer

Expert witnesses are engaged for both plaintiff and defendant clients, and while the general approach is the same, there are some important differences. Moreover, experts with solid experience on both sides enjoy a number of advantages—both in opportunities, and in court.  

Broadly the Same… 

No matter who the client is, plaintiff or defendant, experts are expected to adhere to the same ethical code. Which side you are on does not play a role in your expert opinion. Expert Dan Arthur makes no distinction, “I work for plaintiffs, defendants, state governments, the federal government, and private entities; I will come up with one opinion. I do not care which side [it is for].” 

Dr. Steven Feinberg agrees, applying his medical expertise wherever it is helpful, “Another thing I would tell my younger colleagues and would have told myself 50 years ago when I started, is that it is so important to see yourself as being helpful to the case in general. What that means to me is that whether it is a defense case or a plaintiff case, it is my role to help the attorney understand the medical part.” 

…But There are Differences 

The engaging attorney may strategize differently as plaintiff’s versus defendant’s counsel, which will affect your performance (but not your opinion). Professor Gil Fried notes a common strategy, “On the defense side my goal is only ‘how do we destroy the other sides expert?’ On the plaintiff side, my approach is [to ask], ‘how do I present it in such a simple and straightforward way that no one can really attack what I proposed?’” 

Another difference expert witnesses will encounter is in writing responses and rebuttal reports for the defense. According to Dr. Michael A. Einhorn: 

[A] plaintiff expert must establish reliable proof of damages in the first place, and a sufficient causal connection from the purported infringement to the sought remedy. [. . .] If I am working as a defense expert, some attorneys like a direct rebuttal, while others prefer to add an affirmative valuation. With the latter type of report, we are able to neutralize the other, and then put up what we think is the right valuation for the matter if it does go to court. 

Expert John Lauhoff notes the back-and-forth between report and rebuttal, “As far as depositions are concerned, when it comes to reviewing them, the plaintiff always gives the deposition first. Then the defense expert has an opportunity to look at that report and pick it apart and then the plaintiff would have an opportunity to go back and pick the defense report apart.” 

A Leg Up 

Working a mix of engagement types affords experts some insight into the opposing side’s strategy. Dr. Jill Cramer finds it crucial, “The most important piece of advice I can give to an expert is to make sure you work for the defense and the plaintiff. It will make you a well-rounded witness and help you understand both sides of the case. It strengthens the impact of your statement if we understand where we fit in the whole process, strengthens our opinion, and helps the lawyer make a stronger case.”  

Dr. Laura Miele concurs, adding “Always picture if you were on the plaintiff or you are on the defense, whatever side you are on, think about what the opposite side would do and how you would work up the case if you take the case. How would you work up the case? That will help you.” 

Expert John Hughett’s experience lends him some intuition before walking into a deposition, “Before a deposition, I have an idea of what the other side is going to ask me because I do both defense and plaintiff work. [. . .] I know what [opposing council] does not like so I take the ‘do not likes’ and try to reduce that into questions that might be asked [and] then I go over it with the attorney.” 

For this reason, attorneys may prefer experts with significant experience on both sides. Expert Lauhoff recommends a strong blend, “I work both plaintiff and defense cases, it’s extremely important to get a mixture like that because a lot of attorneys say, ‘Boy, I really like that, having the combination of plaintiff and defense experience.’” 

Prevent the Appearance of Bias 

A common tactic to impeach expert witnesses is to reveal potential bias. One of the ways attorneys accomplish this is pointing out when experts rely solely or chiefly on one type of client. By maintaining a good mix of plaintiff and defendant engagements, these tactics have little sway.  

Dr. Cramer recalls, “I have had attorneys try to prove that I am either defense-heavy or plaintiff-heavy. Whenever they have got ahold of my list of cases, they see that I do more plaintiff work because of the lawyers who have utilized me in my area. I do a good amount of defense work as well. If there is a defense attorney who wants to prove that I do not do defense, they are going to be disappointed in my resume.” 

Expert James Lewis expands on this, recalling “I’ve been called a casual observer. I’ve been called uninformed. I’ve been called a hired gun. That’s why I do 50% plaintiff and 50% defense. That is important to me, and I’ll tell any expert to go that route, if possible.”  

Expert CVs are available to opposing counsel, and they will use it against you if there are too many similar engagements. Dr. David Williams remains vigilant, “One of the things I found out during the trial is that [the opposition] will look at your resume and go over cases you have been in, and [whether you worked for] the plaintiff or defendant, [and if] they were those with deep or shallow pockets. They would ask that kind of stuff, and I have made a conscious effort to make sure that I get a good mix of 50/50 defendants and plaintiffs.” 

Getting More Work 

Working with one side may lead to an engagement from the other if your performance is convincing, yet sober. Professor Fried is frequently hired by opposing counsel, which is a great way to maintain a good mix of engagement types: 

I find that when you do a good job, people take notice; I can’t tell you how many times I’ve been on the plaintiff’s side in a case [. . .] and the second the case is over, I get a phone call from the opposing counsel saying, “We like how you work. We have two cases that are defending right now. Can we use you as your expert witness?” I think that’s the ultimate compliment because I wasn’t outlandish. I wasn’t trying to raise any crazy theories or saying that is not defendable and I think attorneys respect that.  

Mr. Lewis suggests getting referrals from within your company where possible: 

If you only do plaintiffs cases or if you only do defense work that can be a problem. I just tell folks to get started [by] working inside your company. If you’re a safety manager, work inside your company with your corporate counsel. [. . .] Branch out a little; get a referral from your corporate counsel to work for an attorney (who might be a plaintiff’s attorney) and work that side of it with the knowledge you’ve gained on your job. 

Gain strategic foresight with a blend of engagement types and enjoy the advantages when getting hired and performing in court. Remember that your CV may reveal any client-type biases, and don’t overlook opportunities to work for former opposition.  

If you are interested in expert witness work, consider signing up with Round Table Group. For over 30 years, we have helped litigators locate, evaluate, and employ only the best and most qualified expert witnesses. Contact us at 202-908-4500 for more information or sign up now!