Basis of Expert Opinion Fair Game on Cross: Ill. App. Court

Cross-examining expert witnesses about the sources of evidence their opinions are based on is the right of opposing counsel, an Illinois appellate court has ruled, reversing the lower court. All of which arose when the trial court prohibited opposing counsel from mentioning the ambiguous evidence the expert based his opinion on.

In Karn v. Aspen Commercial Painting, Inc., 2019 IL App (1st) 173194, the plaintiff, Sweta Karn, sued the defendants, Scott Gilman, and his employer, Aspen, for damages after Gilman ran over her foot at an intersection in Chicago.

The defendants commissioned an investigative report and retained Dr. Oleg Petrov, a podiatrist expert witness, who reviewed the details provided to him, including a surveillance video which was part of the investigative report. Dr. Petrov then provided his written expert opinion, based in part on the video.

Karn retained her podiatrist and surgeon, Dr. Dean Stern, as one of her expert witnesses. Karn's counsel questioned Dr. Stern about the surveillance video, who responded that the person in it was “not your client.”

Later in the proceedings, the defense counsel asked Karn if she “ever worked at an eyebrow threading place.” Striking the question, the trial court asked how it was relevant. Defense counsel explained that he had served a Request to Admit on Karn that she was the person in the surveillance video, but she had denied that it was her.

The trial court inquired at length as to who was depicted in the video. Failing to get a clear answer from the parties, the court barred any further “mention about the video surveillance, period.”

Reviewing Dr. Petrov's written report, the trial court found that it referred to “[a]n individual purported to be Ms. Karn,” that the “individual” in the video “appeared to be Ms. Sweta Karn” and that Dr. Petrov “assumed” it was her in the video. Dr. Petrov noted in his report that the individual was walking “with a normal gait pattern, and an ability to ambulate in standard shoes without gait assistive devices.” He emphasized the inconsistencies between what the surveillance video depicted and Karn's “claimed limitations in the ability to stand and walk.” Based on those alleged inconsistencies, Dr. Petrov ultimately concluded that “no future pain, suffering, and/or disability are expected to continue.”

Even though Dr. Petrov admitted that he relied on the video to form his opinion, the trial court found that he did not refer to the person in the video as Karn, and allowed Dr. Petrov to testify as to the “severity and permanence” of Karn's injuries.

Karn's counsel asked for permission to cross-examine Petrov about the video, arguing that it formed the basis for Dr. Petrov's opinion. The trial court denied the request.

The jury awarded Karn $123,375 for pain and suffering, disability, and disfigurement, but also found her 40% contributorily negligent and that she failed to mitigate her damages, reducing the award to $70,500.

Karn filed a motion for a new trial, arguing that the trial court erred when it limited the cross-examination of Dr. Petrov as to the basis of his opinion and that the jury's award of damages was manifestly inadequate.

The Illinois 1st District Appellate Court found that, while the scope of cross-examination rests within the discretion of the trial court, Karn was clearly entitled to question Petrov about the surveillance video because it formed part of the basis of his opinion:

“The facts, data, and opinions that form the basis of the expert's opinion, but that are not disclosed on direct examination, may be developed on cross-examination.

Precluded from questioning Dr. Petrov about the the surveillance video by the trial court, Karn's counsel was unable to argue to the jury that Petrov's reliance on the video rendered his entire opinion unworthy of belief. The appellate court found that the trial court's error materially affected the outcome of the trial, reversed the trial court and remanded for a new trial.

Assuming Dr. Petrov had not based his opinion on a video of the wrong person, or that defense council was able to actually prove the video was of the right person, the issue would not have arisen.

Basing an opinion on, at best, ambiguous evidence might normally result in the opinion being excluded. While it seems to have squeaked by this trial court, the odds of a repeat would seem unfavorable.