For as long as I have been practicing law, now 37 years, the question an expert must always be asked is whether his or her opinion is to a reasonable degree of certainty. Once that question is answered in the affirmative, the burden for the offering expert is whether the opinion that is about to be given improving the strength of the expert witness’s opinion is more probably true than not. That second question must be answered affirmatively as well.
In a recent deposition of one of my experts, one of the defendants’ lawyers spent a great deal of time badgering the witness about what she believed the term reasonable degree of medical certainty means since it was stated in that fashion in her written opinions. The answer went something like this: “I have never been asked this before.” The defense counsel argued with the witness, saying that she did not correctly state what he said was the “test in Illinois,” for reasonable certainty. I am not aware of any law that requires an expert to define what reasonable certainty means before answering, since it is a set of words that are understandable on their face. This witness testified that she believed it was more probably true than not that the injury suffered by the plaintiff was caused by the negligence of the defendants.
To dig deeper in this, “reasonable certainty” is a statement that the opinion is not a guess or speculation, but the product of some scientific method or from the education, background and experience of the expert.
The important part as to the admissibility of an expert’s testimony is that the opinions are given to a reasonable degree of certainty and that if causation is the purpose of the testimony, the expert must state whether the cause of the injury or event might or could have been caused by the acts, omissions or neglect of the defendant or more probably true than not, could have been caused by the acts or omissions of a party. In brief, it is the plaintiff’s obligation to show to the jury or the fact finder, that more likely than not, the defendant’s negligence was a cause of the plaintiff’s injury. Even if the expert testifies that the cause of the injury is possible from the defendant’s conduct that would be sufficient to go to the jury for consideration, but is weakened by the term “possible.”
In cases where the issue is future damages, for example, an expert would be asked to a reasonable degree of certainty to give testimony that these damages would occur in the future to a degree of probability. The more probability there is, the more likely that the jury would agree with the notion that future damages should be awarded. The expert could testify that it is more probably true than not that the party will suffer future damages in the future. As long as the party can show through expert testimony that there is an increased risk of future injury or damages, the jury could consider that element of damages so long as “it can be shown through a reasonable degree of certainty that the defendant’s wrongdoing created the increased risk.” Dillon v. Evanston Hosp.,199 Ill.2d 483, 500 (2002).
The challenge is to make sure that the distinction between reasonable certainty and more true than not is clear and concise.
Kreisman Law Offices has been handling civil jury trials for individuals, families and businesses for more than 37 years in and around Chicago, Cook County and its surrounding areas, including Palatine, Rolling Meadows, Elmhurst, Hickory Hills, Worth, Robbins, Crestwood, Park Forest, Chicago (Burnside, Pullman, Lake Calumet), Maywood and River Forest, Ill.
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