In Be Alert for the “Hybrid” Witness Editor-in-Chief of Daubert Online Patrick J. Kenny writes:
Until the law on the issue settles there are some practical steps counsel should take to address hybrid witnesses:
(1) Make sure that the witness really is a “hybrid” witness. The fact that the witness happens to be a treating physician, for instance, might not be the end of the analysis. See, e.g., Kirkham v. Societe Air France, 236 F.R.D. 9, 12-13 (D.D.C. 2006) (noting that a treating physician may be “retained or specially employed” under Rule 26 and thus an expert from whom a report is required if, among other things, they base opinions on something other than their own examination of the party such as the medical records of another physician or if they are compensated or expect compensation for their time preparing to testify);