Arizona Supreme Court holds that a fact witness may also offer expert opinion testimony based on personal observation and participation without violating the One Expert Rule.

An injured patient saw a series of physicians at different facilities after which he had severe injuries and complications.  His conservator sued a group of physicians and facilities, alleging that an error in recording of lab results delayed his diagnosis and worsened his condition.  At trial, certain treating physicians testified regarding the care they provided; the plaintiff argued that the testimony duplicated testimony on the standard of care offered by the defense’s retained expert.  The plaintiff alleged that this duplicative testimony violated the so-called One Expert Rule.  In addition, one of the defendant-physicians had been dismissed on summary judgment.  Another defendant moved to name the dismissed physician as a nonparty at fault, which the trial court denied.  On appeal, the court of appeals held that the treating physician testimony violated the one-expert rule.  In addition, the court dismissed a cross-appeal from the denial of the motion to name a nonparty at fault on the grounds that the dismissed physician was an indispensable party to the cross-appeal who needed to be notified of the cross-appeal.

The Supreme Court vacated, holding that a defendant may present testimony by treating physicians on the standard of care they provided and also present testimony from a retained expert on the standard of care without violating the so-called One-Expert Rule under Rule 26(b)(4)(F)(i).  Under that rule, each side of a case is presumptively allowed to call only one retained expert to testify on an issue.  Testimony from a treating physician on that physician’s own standard of care does not violate the One-Expert Rule when the testimony is based on that physician’s own observations and personal participation in providing treatment to the plaintiff. 

Separately, the Court held that if a treating physician-defendant is dismissed on summary judgment, that dismissed party is not an indispensable party to an appeal from the denial of a motion seeking to name that dismissed party as a nonparty at fault.

Justice Montgomery authored the unanimous opinion.

Posted by: Annabel Barraza