Expert Witness Blog
Plaintiff sued defendant after slipping and falling on cherries. The plaintiff hired a Mechanical Engineering Expert Witness to provide testimony in the case. The defendant filed a motion to exclude this testimony, which was granted in part and denied in part by the court.
Facts: This case (Briley v. Wal-Mart Stores, Inc. – United States District Court – Southern District of Texas – January 3rd, 2018) involves a personal injury claim. The plaintiff alleges that she slipped and fell on cherries that had fallen to the floor. The defendant’s policy entails placing floor mats around displays of produce to reduce the risk that customers will slip on fallen fruit. However, there were no floor mats around the cherry display at issue. The plaintiff has sued for negligence against the defendant and has hired Mechanical Engineering Expert Witness, Dr. Jahan Rasty, Ph.D. The defendant has filed a motion to exclude the expert witness testimony of Dr. Rasty.
Discussion: Dr. Rasy will be testifying on friction and the slippery nature of cherries as well as store policies and the reasonableness of the defendant’s actions.
First, Dr. Rasty measured how the dynamic coefficient of friction (DCOF) between the bottom of a flip flop and a tiles surface varies with different floor coverings and the presence of cherries. The defendant argues that Dr. Rasty measured a typical flip flop on a typical floor without replicating the exact flip flop that the plaintiff was wearing, the exact tile at the store, or the exact mats that the defendant uses. The court opines that arguments like this go go the weight of the evidence and not the admissibility and can be addressed through cross-examination.
In addition, the defendant argues that Dr. Rasty’s DCOF opinions are very basic and within the common sense of the trier of fact and should thus be excluded. That said, the court opines that a jury would find Dr. Rasty’s testimony of so little value that it should be excluded in its entirety and will deny in part the defendant’s testimony regarding the DCOF analysis.
Also, the court opines that it will exclude the testimony of Dr. Rasty as it applies to the reasonableness of the defendant’s policies, whether they were observed at the time of the accident, and whether the failure to follow these policies cause the plaintiff to fall. First, the court states, there is nothing in Dr. Rasty’s experience or training that qualifies him as an expert on these issues. Second, he has not compared the defendant’s safety policies to other retailers. Last, Dr. Rasty’s opinion on the defendant’s alleged unreasonableness and the accident’s cause is a legal conclusion that is not allowed under Daubert.
Conclusion: The motion to exclude the expert witness opinion of Dr. Jahan Rasty, Ph.D. is granted in part and denied in part.