At one time or another every trial lawyer has or will encounter the frustrating circumstances of an attempted sandbag on the eve of trial.  Faced with this issue, trial judges sometimes grant leniency and permit the evidence.  Recently, the Court of Appeals rejected a trial court’s leniency to a last-minute expert witness.  The Court instructed: “[t]rial judges do right by spotting and squelching … foul tactic(s).”

In McDonald v. Zargaryan, 2025 WL 3704598, Plaintiff’s counsel offered a last-minute, untimely expert witness in a personal injury action 7 days before trial.  Not entirely unusual, the judge permitted the expert so long as a deposition occurred.  That resolution imposed an undue burden for the other side of the case at the very busiest time in a case.  For example, here, the expert was deposed in the midst of jury selection.

The outcome was a jury returned approximately a $14 million judgment.   On appeal the decision was overturned.  By way of context, expert witnesses are ordinarily disclosed roughly 50 days before trial.  Plaintiff wished to add a witness 7 days before trial.  The problem is that Plaintiff’s counsel failed to file a motion to augment the expert witness list.  The California Code of Civil Procedure § 2034.610(a)(1) specifies the procedure where expert witness lists might be changed after the deadline for the disclosure of expert witness lists.  The moving party must support the motion by good cause and explain the last-minute change.

Here, Plaintiff’s counsel did not follow this procedure and the “new expert” was someone the Plaintiff’s firm had retained on a separate case.  And now we get to the meat of this case.  The case itself stemmed from a traffic collision that occurred at “walking speed”.  The Plaintiff left the scene without medical treatment.  In the six years before the last-minute surprise expert witness there was no medical evidence of any recommendation that Plaintiff required spinal surgery.

The new expert testified that spinal surgery was required at a cost of nearly $2 million in future medical treatments.  The jury then apparently relied on the new expert’s opinion and awarded $2 million in past pain and suffering, nearly $2 million in future medical costs and $10 million in future pain and suffering damages.

Remarkably, Plaintiff had testified that his condition had not worsened.  After the accident Plaintiff continued snowboarding, rollerblading, and motorcycling.  In fact, Plaintiff rollerbladed the day before and after seeing the last-minute surprise expert witness.

This decision is instructive.

If an unfair or extraordinary situation strikes trial counsel where a previously retained and disclosed expert witness becomes unavailable, trial counsel must file a motion to augment the expert witness list and demonstrate good cause (such as death, illness, or lack of capacity).  This may seem especially difficult at a time where trial preparation time is the primary focus, but it is required.

On the other hand, the Court must act as a gatekeeper and not allow improper trial tactics to proceed where the discovery rules have not been followed.  Unfair tactics and sandbags at trial should not be permitted.

Randy Sullivan is a partner at Patton Sullivan Brodehl LLP specializing in business and real estate litigation. Learn more at https://psblegal.com/randy-sullivan.html