Plaintiff medical expert reports fail Daubert challenges for a limited set of identifiable reasons. The analytical defects are the mirror image of the defects found in defense IME reports — and they are equally predictable. A physician who has applied the same criteria framework from the payer side can identify them with the same precision.
The common failure modes
Confidence that exceeds the evidence: the expert states a causation opinion "to a reasonable degree of medical certainty" but the record does not support that confidence level. This is the most common and most exploitable defect. Selective evidence citation: the expert cites supporting evidence and does not address contradictory evidence. At Daubert, the question is whether the expert considered all relevant evidence — not just the evidence that supports the retained opinion. Methodology gaps: the expert's analytical approach does not meet the reliability standards required under Daubert. This includes failure to rule out alternative causation, failure to establish dose-response where required, and reliance on clinical experience alone where the scientific literature requires more.
What a physician analyst identifies
The same seven-defect analytical framework applied in IME deconstruction works in reverse for plaintiff expert reports. Unsupported assertions, omitted contrary evidence, internal contradictions, selective guideline citation, confidence misalignment, methodology gaps, and template language mismatches. Each identified defect maps to a specific deposition question or Daubert challenge point.
Why this matters for defense strategy
A thorough plaintiff expert report deconstruction before deposition gives defense counsel the specific questions to ask — built from the report's actual weaknesses, not generic deposition templates. When those questions are physician-authored, they target clinical reasoning vulnerabilities that a non-physician questioner might miss.