Day in the life of an Expert Witness

The claimants, who own a property adjoining with the properties of the defendants, complained that the defendants engaged in various acts of trespass on, and damage to, their property. The claimants’ expert, who replaced a retiring expert, referenced and relied on a key, but erroneous, “fact” in his predecessor’s report without checking it.

The claimant alleged that the second defendant, a Spanish racing driver, had repudiated a binding agreement under which he was contracted to drive for the claimants’ IndyCar team for the 2024, 2025 and 2026 racing seasons. The judge found some of the expert witnesses to be impressive and independent, while the expert evidence of others was unimpressive and disappointing.  

This case illustrates the factors taken into account in Scotland in deciding whether to grant an application for certification of an expert which is necessary if the charges of a skilled person are to be recovered from other parties by way of judicial expenses.

Grant v Lothian Buses LTD [2025] CSOH 98

The case was a group litigation concerning extensive oil pollution which affected two regions in the Niger Delta in Nigeria. The judge rejected the strident criticism of the experts who were called to provide evidence on aspects of Nigerian law.

It appears that in this case an expert recommended the appointment of an intermediary without understanding the role of an intermediary. The court did accommodate proper breaks and ensured clear explanations as to the charges faced.

R v Sartip-Zadeh [2025] EWCA Crim 1250

The defendant was contracted, during the Covid lockdowns, to source and supply sterile gowns, which the claimant subsequently asserted were not contractually compliant. Issues for expert evidence included the sterility of the gowns and whether the claimant could have mitigated the loss by resale.

The Court excluded consideration of the expert testimony of an expert on the dangers of AI and misinformation, after he submitted an expert declaration which included fake AI-generated citations to two academic articles.

Kohls v. Ellison, 2025 WL 66514 (D. Minn. Jan. 10, 2025)

The two handwriting experts in this case were given completely different samples of comparator signatures and did not undertake the same task. The judge noted that it was extraordinary and unsatisfactory that the defendants’ expert was provided with comparator signatures which were not the person’s normal signature and was then instructed to assume they were authentic.