Practical Tips · The Capstone · Presumptions & Burdens · July 2026
Every factor in this series builds to one moment: the burden flips from claimant to insurer. Here is the access principle behind that shift, and the question the law hasn’t settled.
Compensation data. Retention volume. Outcome patterns. Every factor this series has covered exists to do one thing: build toward the moment a court decides the insurer, not the claimant, has to answer for its expert’s neutrality. That moment has a name — a presumption — and a distinct, related question that gets far less attention: who carries the burden, and does it shift, at each stage of the case.
A claimant wants to show the insurer’s retained expert has a pattern of ruling against people like her. Who has that information? Not her — the insurer does. This is not a new kind of problem. When an employer’s payroll records are too sloppy for an employee to prove her exact hours, the law shifts the burden to the employer, because the employer alone could have kept the records. When a hospital patient wakes from surgery with an unexplained injury, the law presumes negligence against everyone who had control over her care, because she alone had no way to know who was responsible.
When one party controls the evidence and the other cannot get at it, the burden moves to the party with the access. That is not a special insurance rule. It is what fairness already requires whenever the imbalance is this lopsided — and insurer-retained experts are the same imbalance in different clothes.
The clearest working version of this comes from Demer v. IBM Corp. LTD Plan, the Ninth Circuit’s 2016 decision that anchors this series:
| Step 1 | The claimant makes a modest showing — volume and compensation data enough to raise a fair inference of financial conflict. Not proof of actual bias. |
|---|---|
| Step 2 | The burden shifts to the insurer to answer that showing — with evidence there was no conflict, or that it took real steps to guard against one. |
| Step 3 | If the insurer could have kept records showing its expert’s neutrality and didn’t, that silence counts against it — a “missed opportunity,” in the court’s own words, not a neutral gap. |
| Step 4 | The court calibrates how much skepticism the record actually supports. |
Notice what step one does not require: a confession, or proof of a corrupt motive. Just a modest structural showing — because the insurer, not the claimant, is the one who could have kept the records that would settle the question either way.
Demer itself, read as a story about what each side did and did not do with the record in front of them, is the module’s case study — see A Rebuttable Presumption in the Plaintiff’s Favor.
Demer is an ERISA case, and ERISA comes with real limits a first-party insurance claimant does not share — no bad-faith tort, no independent duty to investigate fully and fairly before denying a claim. If the access principle justifies shifting the burden under those more constrained federal rules, it has at least as much force where state law already imposes an affirmative duty to investigate before the insurer ever gets to deny.
Read the deep-dive → See the bias-evaluation service →
The record-building case study behind this doctrine: A Rebuttable Presumption in the Plaintiff’s Favor. The six steps distilled to a field card: Presumptions and Burdens: A Practitioner’s Checklist. This page is the capstone of the series that begins with The Standard Comes Before the Factors and runs through The Two Metrics That Trigger the Burden-Shift, The Bias You Can Read in the Report Itself, and The Bias Factor Everyone Argues Wrong. The full paradigm — standard, factors, and presumption together — is set out in Demer’s Paradigm for Assessing Biased Insurance Experts (Advocate Magazine, 2024).
Distilled from the project’s own doctrinal synthesis of the presumption and burden-shifting case law (Demer v. IBM Corp. LTD Plan; Metropolitan Life Ins. Co. v. Glenn; Abatie v. Alta Health & Life Ins. Co.) and its access-principle analogues (Estate of Barton v. ADT Sec. Servs. Pension Plan; Ybarra v. Spangard). Case law is cited for its principles. Educational and informational only; not legal advice.