GAQM Exam CFA-001 Topic 1 Question 11 Discussion

According to US federal rules, to present a testimony in a court of law, an expert witness needs to furnish certain information to prove his eligibility. Jason, a qualified computer forensic expert who has started practicing two years back, was denied an expert testimony in a computer crime case by the US Court of Appeals for the Fourth Circuit in Richmond, Virginia. Considering the US federal rules, what could be the most appropriate reason for the court to reject Jason's eligibility as an expert witness?