Questions relating to the bases and sources of an expert's opinion affect the weight to be assigned that opinion, not admissibility; Court admits the testimony of Structural Engineering Expert Witness in insurance coverage dispute

Questions relating to the bases and sources of an expert’s opinion affect the weight to be assigned that opinion, not admissibility; Court admits the testimony of Structural Engineering Expert Witness in insurance coverage dispute

This insurance coverage dispute arose when the Plaintiff, Fiberco’s building was damaged by a hailstorm in April 2020 while insured under a policy issued by Defendant, Acadia Insurance Company effective from April 10, 2020 to April 10, 2021. FiberCo subsequently filed a claim with Acadia for the hail damage to the building. After an assessment, Acadia’s engineer identified at least seven places on the roof of the building with openings at the seams of overlapping metal panels, which reduced the water shedding capability of the roof in those areas, and additional hail dents. Acadia denied FiberCo’s claim, explaining that while the seven open seams were considered a covered loss, the dents to the roof fell under the Policy’s cosmetic damage exclusion. Consequently, the overall amount of the covered loss was deemed to be below the Policy’s deductible amount. In response, FiberCo initiated legal proceedings by filing a lawsuit against Acadia Insurance Company and also Union Standard Lloyds, underwriter of the insurance policy to which Fiberco and Acadia Insurance Company (Acadia) were parties.

During discovery, Fiberco’s expert David Day provided a report concluding that all of the building’s metal roofing needed replacement due to the functional damage arising from the hail and the wetted insulation also needed replacement. He also opined that the hail dents which have not opened seams would cause accelerated corrosion and reduce the roof’s useful life by 25%. Fiberco provided initial expert designations and first amended designations to Acadia and Union, which had listed Day as a retained expert. Acadia and Union then deposed Day and learned his assistant, not Day himself, had inspected Fiberco’s building. Later, Day personally inspected the building for the first time. Fiberco subsequently filed a second amended expert designation for Day, after the deadline and without leave of court. The second designation did not include a supplemental report or declaration from Day at that time, but stated Day’s testimony would rely on his previous deposition and later inspection of the property. 

Acadia and Union Standard moved to strike Day’s expert testimony, objecting to Day’s characterization of the dents as “functional” and questioning the scope and reasonableness of the necessary repairs to FiberCo’s building. They argued that Day’s opinions lacked a basis in reliable facts or data, were not the product of reliable scientific principles and methods, had not applied any reliable principles and methods to the facts of the case, and did not aid the trier of fact. Additionally, they claimed that Day’s second expert designation was untimely and prejudicial.

Structural Engineering Expert Witness 

David Vaughan Day holds a Bachelor of Science in Construction and is a registered professional engineer and an expert in foundation and structural defects in residential and commercial construction. He has been a structural forensic engineer since 1998 and has performed over 1,000 structural forensic inspections, and at least half are wind/hail assessment inspections. Day is the President and Chief Engineer for CASA Engineering, L.L.C., and has been designated a Diplomate in Forensic Engineering Board by the National Academy of Forensic Engineers.

Discussions by the Court

Federal Rule of Evidence 702 governed the admissibility of expert testimony, allowing opinion testimony from qualified experts if it assisted the trier of fact and met specific criteria. The Court, acting as a gatekeeper, required the party presenting expert testimony to prove its reliability and relevance by a preponderance of evidence. Expert testimony was considered relevant if it aided in understanding the evidence or determining a fact in question, aligning with Federal Rule of Evidence 401. Reliability necessitated scientifically valid reasoning or methodology, avoiding subjective belief or unsupported speculation. The Court, applying the Daubert factors, assessed the reasonableness of the expert’s approach rather than focusing solely on the conclusions drawn.

The crux of the dispute concerned the reliability of Day’s testimony and the timeliness of the second amended expert designations. As an initial matter, however, Day was clearly qualified, and his reports were relevant to the issues in the case. His reports were also relevant to the issues in the case; in fact, they were highly relevant. Day’s report provided information concerning whether the building had suffered hail damage and the extent of the damage—both issues at the heart of the dispute. Thus, Day’s testimony was considered relevant because it assisted the trier of fact in determining facts in issue.

Testimony was deemed reliable when “the reasoning or methodology underlying the testimony is scientifically valid.” Acadia and Union had urged the Court to strike Day’s expert testimony, asserting that his opinions on accelerated corrosion and microfractures lacked support from reliable sources or data and were contradictory to the publications Day referred to. FiberCo countered that these opinions were based on Day’s personal observations and experience, arguing that the Defendants’ objections were suitable for cross-examination but not grounds for striking Day’s testimony. The Court sided with FiberCo, emphasizing deference to the jury’s role in resolving conflicting expert opinions. It held that questions regarding the bases and sources of an expert’s opinion affected the weight assigned to the opinion rather than its admissibility, leaving such considerations for the jury’s deliberation.

Ultimately, the Defendants sought to strike Day because they disagreed with his application of scientific methodology to the facts of the case, asserting that he misinterpreted the publications he relied upon. The Court, considering this disagreement, emphasized that the traditional and appropriate methods for addressing shaky but admissible evidence were vigorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof. Consequently, the Court denied Acadia and Union’s motion to strike Day.

The Court, however, had taken issue with the untimeliness of FiberCo’s second amended expert designations, its failure to seek leave from the Court, and its misrepresentation that Day had examined and inspected the property, which he had not personally done. The Court found that Acadia would be unfairly prejudiced without the chance to depose Day after he had inspected the property, especially given that FiberCo had led Acadia to believe Day had already done so before his deposition. As a result, the Court had ordered that Acadia be given the opportunity to redepose Day, if it chose to, at FiberCo’s expense.


The Court denied the motion to strike Day’s expert testimony. The Court found him qualified, his opinions relevant, and arguments about his factual bases went to weight rather than admissibility. However, the Court agreed the late expert designation was prejudicial, so it ordered Day to be re-deposed by Acadia about his late personal inspection at Fiberco’s cost. The Court has not arrived on an outcome for this case since the remaining issues involved in this case still await resolution.

Key Takeaways

This case demonstrates that objections with regard to an expert’s factual bases and application of methodology generally call into question the weight assigned to the testimony, not admissibility. The Court rejected Acadia’s motion to strike Day’s testimony despite Acadia’s arguments that Day misapplied the science. The Court stated that vigorous cross-examination is the appropriate means to address shaky expert opinions. However, this case also shows that unfair prejudice from a late expert designation can warrant a supplemental deposition. Here, Acadia relied on Day having inspected the property when deposing him initially. Allowing a late inspection and designation without a new deposition would be prejudicial. Finally, Courts consider if the opinions will assist the trier of fact, meaning they must be relevant to disputed issues. Courts act as gatekeepers to admit only useful expert testimony.