Expert Witnesses in High-Stakes PI: Tactical Choices That Move (or Sink) the Case

In modern tort practice, almost every significant case is an expert case. Whether you are prosecuting birth injury malpractice, a catastrophic trucking collision, or a products case with engineering and human-factors layers, the outcome will often turn less on “what happened” and more on who explains it and how.

That reality creates a tension for plaintiffs’ lawyers. The right expert can transform a “maybe” case into a policy-limits resolution or a seven-figure verdict. The wrong expert can quietly erode value for two years and then implode at Daubert, summary judgment, or on the first morning of trial.

At Berman & Simmons, a large part of our work involves cases where the expert landscape is complicated, expensive, and unforgiving. The goal of this article is not to give away a playbook, but to share some of the questions we think about when we decide whether a case – and a proposed expert – is truly trial-worthy.

Start With the End of Trial in Mind

Most lawyers start with, “I need an expert.” That’s too vague. Before you retain anyone, picture the end of the case:

• What exact issue must this expert carry across the line for you?
• Is it liability in a highly specialized standard-of-care setting?
• Is it a causation gap that will decide summary judgment?
• Is it future damages, life expectancy, or economic loss where the numbers move the needle from five to seven figures?

We draw a hard distinction between:

• “Must-have” opinions: The bare minimum you need to survive dispositive motions and satisfy your burden at trial.
• “Value-add” opinions: The opinions that turn a modest case into a serious one – for example, a life care planner who can responsibly support a substantial future care plan, or a biomechanical engineer who links subtle mechanism of injury to catastrophic sequelae.

If you cannot articulate, in one or two sentences, what you need from an expert and how that opinion fits into your trial story, you are not ready to hire. That’s when experts become line items on a cost sheet instead of levers of case value.

Beyond the CV: Building a Litigation-Grade Expert

A polished CV is the starting point, not the finish line.

In our practice, we assume that anything we don’t know about an expert, opposing counsel will find – and weaponize. Before we commit, we want to understand not just what the expert says about themself, but how they have actually performed in the litigation arena.

We focus on several categories of questions:

• How does this expert present under pressure? Deposition and trial transcripts are more revealing than any résumé. Does the expert teach? Does she stay within the four corners of her expertise? Does she handle hostile cross with composure, or does she argue and wander?
• What is the expert’s litigation footprint? Frequency of testimony, plaintiff/defense split, prior Daubert or other admissibility rulings, and whether courts have described the expert as reliable or criticized methodology. A long list of publications means little if three judges have already excluded the expert on substantially similar issues.
• What does the paper trail say? Articles, presentations, and prior reports can be a gift or a landmine. We look for internal consistency: has the expert taken positions in writing that your opponent will gleefully put on an overhead projector?
• How does the expert allocate time? Some “career experts” are, functionally, professional witnesses. Others are truly active in practice or research and testify only occasionally. Neither is automatically good or bad – but if the jury will view the expert as a hired gun, you want to make that a calculated choice, not a surprise.

The mechanics – which databases to check, which networks to mine for transcripts, how to use verdict and Daubert research – are the kind of infrastructure that rewards repetition. Plaintiff firms that live in catastrophic injury and malpractice work develop systems for this; dabbling makes it much easier to miss the one problem that matters.

Stress-Testing Your Own Expert Before the Defense Does

A common failure mode in plaintiff’s practice is falling in love with an expert early – often because the expert is the first person who tells you, “Yes, you have a case.”

We try to do the opposite: we stress-test our experts before designating them. A non-exhaustive list of uncomfortable questions we ask early:

• Have you ever been the subject of a Daubert or similar challenge? What happened?
• Has any court limited or excluded your testimony? On what grounds?
• Have you taken positions in prior cases or writings that might appear inconsistent with what we’re asking you to say here?
• Are there aspects of this case that are at the edge of your comfort zone? What would you decline to opine on?
• Is there anything in your background – employment history, licensing, prior litigation as a party, disciplinary issues – that a defense firm with time and a research budget might uncover?

The point is not to disqualify every expert who has scars. In high-stakes litigation, most worthy experts have them. The point is to know, now, where those vulnerabilities are and decide whether you can live with them.

If you are not having these conversations early – while you still have time to pivot – you are running malpractice-level risk on your client’s most important witness.

Knowing When the Science Won’t Save You

In many of the cases we see referred to us, the problem is not that the lawyer failed to hire an expert. It’s that the lawyer assumed there must be solid literature to support the expert’s desired opinion – and never verified that assumption.

Two recurring patterns:

1. Emerging or controversial theories. Think trauma-induced fibromyalgia, subtle hypoxic-ischemic brain injury with normal imaging, or low-dose toxic exposures. The medicine may be evolving, and credible experts may be prepared to testify, but the class of testimony is heavily litigated. In those settings, you need a plan for:

• What the best studies actually say (and don’t say).
• How your expert will acknowledge limitations in the evidence without sounding speculative.
• How your jurisdiction’s gatekeeping standard has treated similar opinions.

1. Cases where the expert is over-extended Severely co-morbid patients, multi-factor causation, stretches in future damages. Here, experts are often tempted to bridge gaps with confidence rather than support. The danger is not that the expert is unethical; it’s that you are asking them to answer a question the science cannot answer with the level of certainty you need.

One of the hardest decisions in our practice is to tell a referring lawyer, “We agree something wrong happened here, but the science will not support the causation theory you need for a verdict.” Making that call early – before designations and Daubert – is a lot better than watching your expert disintegrate on cross.

Using Experts Outside the Trial Box

Many lawyers think of experts as something you buy before disclosure deadlines and roll out for mediation and trial. That mindset leaves a lot of value on the table.

In substantial cases, we often use experts:

• At intake, to decide whether the case should be filed at all and, if so, on what theory. A one- or two-hour consult with a high-end specialist can save both you and your client years of sunk time in a case that will never clear causation.
• During written discovery and early depositions, to help frame what really matters. Experts can flag what’s missing in the records, suggest targeted document requests, and help you structure depositions so that you are building the factual foundation they will need.
• In the MSJ phase, to shape declarations that address the defense theory rather than recite generic “standard of care was breached” language. In complex medical malpractice and products cases, we seldom view summary judgment as a mere speed bump; it is a litigation forum we prepare for strategically.
• For mediation and settlement positioning, to calibrate risk. A well-prepared expert who understands the strengths and weaknesses of your case will help you avoid the twin dangers of over-trying a modest case and under-settling a strong one.

This kind of integration takes time and money. For firms that run a high volume of smaller files, it may not be realistic. But if you are sitting on a potential seven-figure injury, treating the expert as an afterthought is a good way to watch that number shrink.

When the Case Calls for a Different Caliber of Expert

There is no shame in recognizing that a case has outrun your expert infrastructure.

Some fact patterns – multi-defendant med-mal, complex product design, industrial incidents with multiple layers of engineering, human factors, and corporate conduct – require:

• Access to national-caliber experts who are already battle-tested.
• Systems for deep vetting of those experts, including prior testimony, verdict history, and admissibility rulings.
• The appetite and resources to front six-figure expert budgets and live with the risk if the jury goes the wrong way.

One of the reasons Berman & Simmons invests so heavily in expert work is because many of our cases come to us from colleagues who have correctly concluded that, for this client and this fact pattern, the safer path is to bring in a firm that does this every day.

Sometimes that means a straight referral; sometimes it means co-counseling and staying involved. Either way, the lawyer who recognizes early that expert issues are going to define the case – and acts accordingly – is doing exactly what the client needs.

Conclusion

We all know that experts are “necessary in almost every tort case.” That’s not new. What separates a routine file from a truly strong case is not simply having an expert, but making disciplined choices about:

• What you truly need the expert to do at trial.
• How rigorously you vet your own expert before the defense does.
• Whether the science can carry the burden you want to put on it.
• When to integrate experts into intake, discovery, and mediation strategy.
• When a case calls for a team that is set up, structurally and financially, to manage high-risk, high-complexity expert work.

Those are judgment calls. They are also, increasingly, the fault lines where difficult cases are either won or quietly lost.