Mary E. Jack, Individually and as Parent and Next Friend of Ella Jack and Owen Jack and Lawrence Laird Jack III, Individually v. Jennifer R. Booth, 858 N.W.2d 711

Mary Jack suffered complications during and after an emergency cesarean; she sued obstetrician Dr. Jennifer Booth (alleging negligent surgery/management) and anesthesiologist Dr. John Sweetman (alleging negligent IV monitoring leading to arm injuries).
Trial proceeded with separate negligence instructions and a verdict form that required the jury to evaluate each doctor’s liability independently.
During trial a juror fainted; Dr. Sweetman (one defendant) rendered medical aid in the courtroom, the juror recovered and was excused, and the court individually questioned remaining jurors about fairness.
The district court denied plaintiffs’ motion for mistrial and later denied their motion for a new trial as to both doctors (finding Booth did not assist the juror and that on-the-spot remedies were adequate).
The court of appeals reversed and ordered a new trial as to both defendants, reasoning the integrity of the trial was compromised and a retrial must be against all defendants.
The Iowa Supreme Court affirmed the district court’s denial of a new trial as to Dr. Booth, vacated the court of appeals ruling on Booth (but left the court of appeals’ new-trial order as to Sweetman intact because Sweetman did not seek further review), and remanded.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether medical aid by one physician-defendant to a juror requires a new trial as to all defendants	Sweetman’s aid created undue goodwill toward physicians generally, tainting jury; new trial needed for both defendants	Partial new trial is permissible because Booth did not assist and the claims were distinct; on-the-scene remedies cured prejudice	Court held partial new trial may be appropriate; denied new trial as to Booth (no abuse of discretion)
Whether a new trial can be ordered as to fewer than all defendants	Jacks: compromise of trial integrity cannot be cured by retrial against some but not all defendants	Defendants: Iowa law permits new trials as to some parties when issues are distinct and separable	Court held Iowa permits partial new trials where issues are distinct and no prejudice results; here claims were separable, so Booth could be excluded from retrial
Standard of review for denial of new trial based on irregularity/prejudice	N/A (procedural)	N/A (procedural)	Denial of new trial reviewed for abuse of discretion; substantial deference to trial court’s on-the-spot judgment

Pavone v. Kirke, 801 N.W.2d 477 (Iowa 2011) (describing abuse-of-discretion review for new-trial motions)
Olinger v. Tiefenthaler, 285 N.W. 137 (Iowa 1939) (recognizing trial court may grant new trial as to some defendants and not others)
Houvenagle v. Wright, 340 N.W.2d 783 (Iowa Ct. App. 1983) (upholding new trial as to one defendant where it would not prejudice others)
Williams v. Slade, 431 F.2d 605 (5th Cir. 1970) (articulating that partial new trials should be avoided unless no injustice results)
Sheridan v. St. Luke’s Regional Medical Center, 25 P.3d 88 (Idaho 2001) (adopting test whether issues are distinct and separable to allow exclusion from a new-trial order)