Caballero v. Tyson Fresh Meats

October 24, 2025

Credible, evidence-based testimony shapes Iowa causation rulings.


On May 16, 2025, the Iowa Workers’ Compensation Commission issued a decision in Caballero v. Tyson Fresh Meats, File No 23005158.01. Deputy Erin Q. Pals ruled in favor of the defendant, who was represented by Jason Wiltfang of Corridorlaw Group Iowa, P.C. 

In her decision, Deputy Pals found that the claimant failed to prove that he sustained an injury which arose out of and in the course of his employment. This finding was shaped in large part by the disparity between the parties’ IMEs. The claimant’s expert’s opinions made broad “blanket statements” regarding causation that cited neither the medical record nor the AMA Guides, the Deputy found. The defense’s expert, on the other hand, related all of his opinions to the medical record and cited the AMA Guides to the Evaluation of Disease and Injury Causation to further support his findings. 

The approach employed by the claimant’s expert, Farid Manshadi, MD, failed to persuade the Deputy that the claimant’s employment caused his injury. Deputy Pals noted the paucity of claimant’s argument on several occasions, observing that claimant’s expert provided no rationale for his opinions despite being the only physician to relate the claimant’s injuries to his activities at Tyson. 

When describing the importance of expert evidence to establishing causation, Deputy Pals noted that “[t]he weight to be given to an expert opinion is determined by the finder of fact and may be affected by the accuracy of the facts the expert relied upon as well as other surrounding circumstances.” Applying that standard to the facts of this case, Deputy Pals found “the blanket, cursory causation opinions of Dr. Manshadi” to be less persuasive than those of the defendant’s experts. This is a lesson that both claimants and defendants would do well to remember. The decision in Caballero is proof that an expert opinion, including the methodology applied and reasoning provided by the expert, has the potential to make or break a case. 

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